diff --git a/src/addon/mod/forum/components/components.module.ts b/src/addon/mod/forum/components/components.module.ts
index e9b656899..0f3bf1b10 100644
--- a/src/addon/mod/forum/components/components.module.ts
+++ b/src/addon/mod/forum/components/components.module.ts
@@ -20,6 +20,7 @@ import { CoreComponentsModule } from '@components/components.module';
 import { CoreDirectivesModule } from '@directives/directives.module';
 import { CorePipesModule } from '@pipes/pipes.module';
 import { CoreCourseComponentsModule } from '@core/course/components/components.module';
+import { CoreRatingComponentsModule } from '@core/rating/components/components.module';
 import { AddonModForumIndexComponent } from './index/index';
 import { AddonModForumPostComponent } from './post/post';
 
@@ -35,7 +36,8 @@ import { AddonModForumPostComponent } from './post/post';
         CoreComponentsModule,
         CoreDirectivesModule,
         CorePipesModule,
-        CoreCourseComponentsModule
+        CoreCourseComponentsModule,
+        CoreRatingComponentsModule
     ],
     providers: [
     ],
diff --git a/src/addon/mod/forum/components/index/addon-mod-forum-index.html b/src/addon/mod/forum/components/index/addon-mod-forum-index.html
index e4d9b273d..9eab4d526 100644
--- a/src/addon/mod/forum/components/index/addon-mod-forum-index.html
+++ b/src/addon/mod/forum/components/index/addon-mod-forum-index.html
@@ -21,7 +21,7 @@
             <core-course-module-description [description]="description" [component]="component" [componentId]="componentId" [note]="descriptionNote"></core-course-module-description>
 
             <!-- Forum discussions found to be synchronized -->
-            <ion-card class="core-warning-card" icon-start *ngIf="hasOffline">
+            <ion-card class="core-warning-card" icon-start *ngIf="hasOffline || hasOfflineRatings">
                 <ion-icon name="warning"></ion-icon> {{ 'core.hasdatatosync' | translate:{$a: moduleName} }}
             </ion-card>
 
diff --git a/src/addon/mod/forum/components/index/index.ts b/src/addon/mod/forum/components/index/index.ts
index 774c8ae4d..036697410 100644
--- a/src/addon/mod/forum/components/index/index.ts
+++ b/src/addon/mod/forum/components/index/index.ts
@@ -19,6 +19,9 @@ import { CoreCourseModuleMainActivityComponent } from '@core/course/classes/main
 import { CoreCourseModulePrefetchDelegate } from '@core/course/providers/module-prefetch-delegate';
 import { CoreUserProvider } from '@core/user/providers/user';
 import { CoreGroupsProvider } from '@providers/groups';
+import { CoreRatingProvider } from '@core/rating/providers/rating';
+import { CoreRatingOfflineProvider } from '@core/rating/providers/offline';
+import { CoreRatingSyncProvider } from '@core/rating/providers/sync';
 import { AddonModForumProvider } from '../../providers/forum';
 import { AddonModForumHelperProvider } from '../../providers/helper';
 import { AddonModForumOfflineProvider } from '../../providers/offline';
@@ -56,6 +59,10 @@ export class AddonModForumIndexComponent extends CoreCourseModuleMainActivityCom
     protected newDiscObserver: any;
     protected viewDiscObserver: any;
 
+    hasOfflineRatings: boolean;
+    protected ratingOfflineObserver: any;
+    protected ratingSyncObserver: any;
+
     constructor(injector: Injector,
             @Optional() protected content: Content,
             protected navCtrl: NavController,
@@ -66,7 +73,8 @@ export class AddonModForumIndexComponent extends CoreCourseModuleMainActivityCom
             protected forumOffline: AddonModForumOfflineProvider,
             protected forumSync: AddonModForumSyncProvider,
             protected prefetchDelegate: CoreCourseModulePrefetchDelegate,
-            protected prefetchHandler: AddonModForumPrefetchHandler) {
+            protected prefetchHandler: AddonModForumPrefetchHandler,
+            protected ratingOffline: CoreRatingOfflineProvider) {
         super(injector);
     }
 
@@ -100,6 +108,22 @@ export class AddonModForumIndexComponent extends CoreCourseModuleMainActivityCom
             }
         }, this.sitesProvider.getCurrentSiteId());
 
+        // Listen for offline ratings saved and synced.
+        this.ratingOfflineObserver = this.eventsProvider.on(CoreRatingProvider.RATING_SAVED_EVENT, (data) => {
+            if (this.forum && data.component == 'mod_forum' && data.ratingArea == 'post' &&
+                    data.contextLevel == 'module' && data.instanceId == this.forum.cmid) {
+                this.hasOfflineRatings = true;
+            }
+        });
+        this.ratingSyncObserver = this.eventsProvider.on(CoreRatingSyncProvider.SYNCED_EVENT, (data) => {
+            if (this.forum && data.component == 'mod_forum' && data.ratingArea == 'post' &&
+                    data.contextLevel == 'module' && data.instanceId == this.forum.cmid) {
+               this.ratingOffline.hasRatings('mod_forum', 'post', 'module', this.forum.cmid).then((hasRatings) => {
+                   this.hasOfflineRatings = hasRatings;
+               });
+            }
+        });
+
         this.loadContent(false, true).then(() => {
             if (!this.forum) {
                 return;
@@ -178,6 +202,9 @@ export class AddonModForumIndexComponent extends CoreCourseModuleMainActivityCom
             return Promise.all([
                 this.fetchOfflineDiscussion(),
                 this.fetchDiscussions(refresh),
+                this.ratingOffline.hasRatings('mod_forum', 'post', 'module', this.forum.cmid).then((hasRatings) => {
+                    this.hasOfflineRatings = hasRatings;
+                })
             ]);
         }).catch((message) => {
             if (!refresh) {
@@ -351,21 +378,9 @@ export class AddonModForumIndexComponent extends CoreCourseModuleMainActivityCom
     protected sync(): Promise<boolean> {
         const promises = [];
 
-        promises.push(this.forumSync.syncForumDiscussions(this.forum.id).then((result) => {
-            if (result.warnings && result.warnings.length) {
-                this.domUtils.showErrorModal(result.warnings[0]);
-            }
-
-            return result;
-        }));
-
-        promises.push(this.forumSync.syncForumReplies(this.forum.id).then((result) => {
-            if (result.warnings && result.warnings.length) {
-                this.domUtils.showErrorModal(result.warnings[0]);
-            }
-
-            return result;
-        }));
+        promises.push(this.forumSync.syncForumDiscussions(this.forum.id));
+        promises.push(this.forumSync.syncForumReplies(this.forum.id));
+        promises.push(this.forumSync.syncRatings(this.forum.cmid));
 
         return Promise.all(promises).then((results) => {
             return results.reduce((a, b) => ({
@@ -476,5 +491,7 @@ export class AddonModForumIndexComponent extends CoreCourseModuleMainActivityCom
         this.newDiscObserver && this.newDiscObserver.off();
         this.replyObserver && this.replyObserver.off();
         this.viewDiscObserver && this.viewDiscObserver.off();
+        this.ratingOfflineObserver && this.ratingOfflineObserver.off();
+        this.ratingSyncObserver && this.ratingSyncObserver.off();
     }
 }
diff --git a/src/addon/mod/forum/components/post/addon-mod-forum-post.html b/src/addon/mod/forum/components/post/addon-mod-forum-post.html
index cad199ead..253e7208a 100644
--- a/src/addon/mod/forum/components/post/addon-mod-forum-post.html
+++ b/src/addon/mod/forum/components/post/addon-mod-forum-post.html
@@ -23,6 +23,8 @@
         </ng-container>
     </div>
 </ion-card-content>
+<core-rating-rate *ngIf="forum && ratingInfo" [ratingInfo]="ratingInfo" contextLevel="module" [instanceId]="componentId" [itemId]="post.id" [itemSetId]="discussionId" [courseId]="courseId" [aggregateMethod]="forum.assessed" [scaleId]="forum.scale" [userId]="post.userid"></core-rating-rate>
+<core-rating-aggregate *ngIf="forum && ratingInfo" [ratingInfo]="ratingInfo" contextLevel="module" [instanceId]="componentId" [itemId]="post.id" [courseId]="courseId" [aggregateMethod]="forum.assessed" [scaleId]="forum.scale"></core-rating-aggregate>
 <ion-item no-padding text-end *ngIf="post.id && post.canreply" class="addon-forum-reply-button">
     <button ion-button icon-left clear small (click)="showReply()" [attr.aria-controls]="'addon-forum-reply-edit-form-' + uniqueId" [attr.aria-expanded]="replyData.replyingTo === post.id">
         <ion-icon name="undo"></ion-icon> {{ 'addon.mod_forum.reply' | translate }}
diff --git a/src/addon/mod/forum/components/post/post.ts b/src/addon/mod/forum/components/post/post.ts
index 92ea42b66..e1d542e3e 100644
--- a/src/addon/mod/forum/components/post/post.ts
+++ b/src/addon/mod/forum/components/post/post.ts
@@ -25,6 +25,7 @@ import { AddonModForumProvider } from '../../providers/forum';
 import { AddonModForumHelperProvider } from '../../providers/helper';
 import { AddonModForumOfflineProvider } from '../../providers/offline';
 import { AddonModForumSyncProvider } from '../../providers/sync';
+import { CoreRatingInfo } from '@core/rating/providers/rating';
 
 /**
  * Components that shows a discussion post, its attachments and the action buttons allowed (reply, etc.).
@@ -44,6 +45,7 @@ export class AddonModForumPostComponent implements OnInit, OnDestroy {
     @Input() trackPosts: boolean; // True if post is being tracked.
     @Input() forum: any; // The forum the post belongs to. Required for attachments and offline posts.
     @Input() defaultSubject: string; // Default subject to set to new posts.
+    @Input() ratingInfo?: CoreRatingInfo; // Rating info item.
     @Output() onPostChange: EventEmitter<void>; // Event emitted when a reply is posted or modified.
 
     messageControl = new FormControl();
diff --git a/src/addon/mod/forum/pages/discussion/discussion.html b/src/addon/mod/forum/pages/discussion/discussion.html
index 65b449476..01be9ede2 100644
--- a/src/addon/mod/forum/pages/discussion/discussion.html
+++ b/src/addon/mod/forum/pages/discussion/discussion.html
@@ -22,7 +22,7 @@
 
     <core-loading [hideUntil]="discussionLoaded">
         <!-- Discussion replies found to be synchronized -->
-        <ion-card class="core-warning-card" *ngIf="postHasOffline">
+        <ion-card class="core-warning-card" *ngIf="postHasOffline || hasOfflineRatings">
             <ion-icon name="warning"></ion-icon> {{ 'core.hasdatatosync' | translate:{$a: discussionStr} }}
         </ion-card>
 
@@ -31,13 +31,13 @@
         </ion-card>
 
         <ion-card *ngIf="discussion" margin-bottom class="highlight">
-            <addon-mod-forum-post [post]="discussion" [courseId]="courseId" [discussionId]="discussionId" [component]="component" [componentId]="cmId" [replyData]="replyData" [originalData]="originalData" [defaultSubject]="defaultSubject" [forum]="forum" [trackPosts]="trackPosts" (onPostChange)="postListChanged()"></addon-mod-forum-post>
+            <addon-mod-forum-post [post]="discussion" [courseId]="courseId" [discussionId]="discussionId" [component]="component" [componentId]="cmId" [replyData]="replyData" [originalData]="originalData" [defaultSubject]="defaultSubject" [forum]="forum" [trackPosts]="trackPosts" [ratingInfo]="ratingInfo" (onPostChange)="postListChanged()"></addon-mod-forum-post>
         </ion-card>
 
         <ion-card *ngIf="sort != 'nested'">
             <ng-container *ngFor="let post of posts; first as first">
                 <ion-item-divider *ngIf="!first"></ion-item-divider>
-                <addon-mod-forum-post [post]="post" [courseId]="courseId" [discussionId]="discussionId" [component]="component" [componentId]="cmId" [replyData]="replyData" [originalData]="originalData" [defaultSubject]="defaultSubject" [forum]="forum" [trackPosts]="trackPosts" (onPostChange)="postListChanged()"></addon-mod-forum-post>
+                <addon-mod-forum-post [post]="post" [courseId]="courseId" [discussionId]="discussionId" [component]="component" [componentId]="cmId" [replyData]="replyData" [originalData]="originalData" [defaultSubject]="defaultSubject" [forum]="forum" [trackPosts]="trackPosts" [ratingInfo]="ratingInfo" (onPostChange)="postListChanged()"></addon-mod-forum-post>
             </ng-container>
         </ion-card>
 
@@ -49,7 +49,7 @@
 
         <ng-template #nestedPosts let-post="post">
             <ion-card>
-                <addon-mod-forum-post [post]="post" [courseId]="courseId" [discussionId]="discussionId" [component]="component" [componentId]="cmId" [replyData]="replyData" [originalData]="originalData" [defaultSubject]="defaultSubject" [forum]="forum" [trackPosts]="trackPosts" (onPostChange)="postListChanged()"></addon-mod-forum-post>
+                <addon-mod-forum-post [post]="post" [courseId]="courseId" [discussionId]="discussionId" [component]="component" [componentId]="cmId" [replyData]="replyData" [originalData]="originalData" [defaultSubject]="defaultSubject" [forum]="forum" [trackPosts]="trackPosts" [ratingInfo]="ratingInfo" (onPostChange)="postListChanged()"></addon-mod-forum-post>
             </ion-card>
             <div padding-left *ngIf="post.children.length && post.children[0].subject">
                 <ng-container *ngFor="let child of post.children">
diff --git a/src/addon/mod/forum/pages/discussion/discussion.ts b/src/addon/mod/forum/pages/discussion/discussion.ts
index ad3da6f2f..d25e6e4d1 100644
--- a/src/addon/mod/forum/pages/discussion/discussion.ts
+++ b/src/addon/mod/forum/pages/discussion/discussion.ts
@@ -23,6 +23,9 @@ import { CoreDomUtilsProvider } from '@providers/utils/dom';
 import { CoreUtilsProvider } from '@providers/utils/utils';
 import { CoreFileUploaderProvider } from '@core/fileuploader/providers/fileuploader';
 import { CoreSplitViewComponent } from '@components/split-view/split-view';
+import { CoreRatingProvider, CoreRatingInfo } from '@core/rating/providers/rating';
+import { CoreRatingOfflineProvider } from '@core/rating/providers/offline';
+import { CoreRatingSyncProvider } from '@core/rating/providers/sync';
 import { AddonModForumProvider } from '../../providers/forum';
 import { AddonModForumOfflineProvider } from '../../providers/offline';
 import { AddonModForumHelperProvider } from '../../providers/helper';
@@ -77,6 +80,11 @@ export class AddonModForumDiscussionPage implements OnDestroy {
     protected syncObserver: any;
     protected syncManualObserver: any;
 
+    ratingInfo?: CoreRatingInfo;
+    hasOfflineRatings: boolean;
+    protected ratingOfflineObserver: any;
+    protected ratingSyncObserver: any;
+
     constructor(navParams: NavParams,
             network: Network,
             zone: NgZone,
@@ -91,6 +99,7 @@ export class AddonModForumDiscussionPage implements OnDestroy {
             private forumOffline: AddonModForumOfflineProvider,
             private forumHelper: AddonModForumHelperProvider,
             private forumSync: AddonModForumSyncProvider,
+            private ratingOffline: CoreRatingOfflineProvider,
             @Optional() private svComponent: CoreSplitViewComponent) {
         this.courseId = navParams.get('courseId');
         this.cmId = navParams.get('cmId');
@@ -147,6 +156,20 @@ export class AddonModForumDiscussionPage implements OnDestroy {
             forumId: this.forumId,
             discussion: this.discussionId
         }, this.sitesProvider.getCurrentSiteId());
+
+        // Listen for offline ratings saved and synced.
+        this.ratingOfflineObserver = this.eventsProvider.on(CoreRatingProvider.RATING_SAVED_EVENT, (data) => {
+            if (data.component == 'mod_forum' && data.ratingArea == 'post' && data.contextLevel == 'module' &&
+                    data.instanceId == this.cmId && data.itemSetId == this.discussionId) {
+                this.hasOfflineRatings = true;
+            }
+        });
+        this.ratingSyncObserver = this.eventsProvider.on(CoreRatingSyncProvider.SYNCED_EVENT, (data) => {
+            if (data.component == 'mod_forum' && data.ratingArea == 'post' && data.contextLevel == 'module' &&
+                    data.instanceId == this.cmId && data.itemSetId == this.discussionId) {
+                this.hasOfflineRatings = false;
+            }
+        });
     }
 
     /**
@@ -210,9 +233,9 @@ export class AddonModForumDiscussionPage implements OnDestroy {
         let hasUnreadPosts = false;
 
         return syncPromise.then(() => {
-            return this.forumProvider.getDiscussionPosts(this.discussionId).then((posts) => {
-                onlinePosts = posts;
-
+            return this.forumProvider.getDiscussionPosts(this.discussionId).then((response) => {
+                onlinePosts = response.posts;
+                this.ratingInfo = response.ratinginfo;
             }).then(() => {
                 // Check if there are responses stored in offline.
                 return this.forumOffline.getDiscussionReplies(this.discussionId).then((replies) => {
@@ -290,6 +313,10 @@ export class AddonModForumDiscussionPage implements OnDestroy {
                 // Ignore errors.
                 this.forum = {};
             });
+        }).then(() => {
+            return this.ratingOffline.hasRatings('mod_forum', 'post', 'module', this.cmId, this.discussionId).then((hasRatings) => {
+                this.hasOfflineRatings = hasRatings;
+            });
         }).catch((message) => {
             this.domUtils.showErrorModal(message);
         }).finally(() => {
@@ -319,7 +346,9 @@ export class AddonModForumDiscussionPage implements OnDestroy {
      * @return {Promise<any>} Promise resolved when done.
      */
     protected syncDiscussion(showErrors: boolean): Promise<any> {
-        return this.forumSync.syncDiscussionReplies(this.discussionId).then((result) => {
+        const promises = [];
+
+        promises.push(this.forumSync.syncDiscussionReplies(this.forumId, this.discussionId).then((result) => {
             if (result.warnings && result.warnings.length) {
                 this.domUtils.showErrorModal(result.warnings[0]);
             }
@@ -334,7 +363,15 @@ export class AddonModForumDiscussionPage implements OnDestroy {
             }
 
             return result.updated;
-        }).catch((error) => {
+        }));
+
+        promises.push(this.forumSync.syncRatings(this.cmId, this.discussionId).then((result) => {
+            if (result.warnings && result.warnings.length) {
+                this.domUtils.showErrorModal(result.warnings[0]);
+            }
+        }));
+
+        return Promise.all(promises).catch((error) => {
             if (showErrors) {
                 this.domUtils.showErrorModalDefault(error, 'core.errorsync', true);
             }
@@ -419,6 +456,8 @@ export class AddonModForumDiscussionPage implements OnDestroy {
     ionViewWillLeave(): void {
         this.syncObserver && this.syncObserver.off();
         this.syncManualObserver && this.syncManualObserver.off();
+        this.ratingOfflineObserver && this.ratingOfflineObserver.off();
+        this.ratingSyncObserver && this.ratingSyncObserver.off();
     }
 
     /**
diff --git a/src/addon/mod/forum/providers/forum.ts b/src/addon/mod/forum/providers/forum.ts
index a7eb0bbae..83f1db720 100644
--- a/src/addon/mod/forum/providers/forum.ts
+++ b/src/addon/mod/forum/providers/forum.ts
@@ -22,6 +22,7 @@ import { CoreUserProvider } from '@core/user/providers/user';
 import { CoreUtilsProvider } from '@providers/utils/utils';
 import { CoreCourseLogHelperProvider } from '@core/course/providers/log-helper';
 import { AddonModForumOfflineProvider } from './offline';
+import { CoreRatingInfo } from '@core/rating/providers/rating';
 
 /**
  * Service that provides some features for forums.
@@ -369,9 +370,9 @@ export class AddonModForumProvider {
      *
      * @param  {number} discussionId Discussion ID.
      * @param  {string} [siteId]     Site ID. If not defined, current site.
-     * @return {Promise<any[]>}      Promise resolved with forum posts.
+     * @return {Promise<{posts: any[], ratinginfo?: CoreRatingInfo}>} Promise resolved with forum posts and rating info.
      */
-    getDiscussionPosts(discussionId: number, siteId?: string): Promise<any> {
+    getDiscussionPosts(discussionId: number, siteId?: string): Promise<{posts: any[], ratinginfo?: CoreRatingInfo}> {
         const params = {
             discussionid: discussionId
         };
@@ -384,7 +385,7 @@ export class AddonModForumProvider {
                 if (response) {
                     this.storeUserData(response.posts);
 
-                    return response.posts;
+                    return response;
                 } else {
                     return Promise.reject(null);
                 }
diff --git a/src/addon/mod/forum/providers/prefetch-handler.ts b/src/addon/mod/forum/providers/prefetch-handler.ts
index f13b34540..03e60a6ba 100644
--- a/src/addon/mod/forum/providers/prefetch-handler.ts
+++ b/src/addon/mod/forum/providers/prefetch-handler.ts
@@ -24,6 +24,7 @@ import { CoreCourseActivityPrefetchHandlerBase } from '@core/course/classes/acti
 import { CoreGroupsProvider } from '@providers/groups';
 import { CoreUserProvider } from '@core/user/providers/user';
 import { AddonModForumProvider } from './forum';
+import { CoreRatingProvider } from '@core/rating/providers/rating';
 
 /**
  * Handler to prefetch forums.
@@ -44,7 +45,8 @@ export class AddonModForumPrefetchHandler extends CoreCourseActivityPrefetchHand
             domUtils: CoreDomUtilsProvider,
             private groupsProvider: CoreGroupsProvider,
             private userProvider: CoreUserProvider,
-            private forumProvider: AddonModForumProvider) {
+            private forumProvider: AddonModForumProvider,
+            private ratingProvider: CoreRatingProvider) {
 
         super(translate, appProvider, utils, courseProvider, filepoolProvider, sitesProvider, domUtils);
     }
@@ -62,7 +64,7 @@ export class AddonModForumPrefetchHandler extends CoreCourseActivityPrefetchHand
             const files = this.getIntroFilesFromInstance(module, forum);
 
             // Get posts.
-            return this.getPostsForPrefetch(forum.id).then((posts) => {
+            return this.getPostsForPrefetch(forum).then((posts) => {
                 // Add posts attachments and embedded files.
                 return files.concat(this.getPostsFiles(posts));
             });
@@ -99,12 +101,12 @@ export class AddonModForumPrefetchHandler extends CoreCourseActivityPrefetchHand
     /**
      * Get the posts to be prefetched.
      *
-     * @param {number} forumId Forum ID
+     * @param {any} forum Forum instance.
      * @return {Promise<any[]>} Promise resolved with array of posts.
      */
-    protected getPostsForPrefetch(forumId: number): Promise<any[]> {
+    protected getPostsForPrefetch(forum: any): Promise<any[]> {
         // Get discussions in first 2 pages.
-        return this.forumProvider.getDiscussionsInPages(forumId, false, 2).then((response) => {
+        return this.forumProvider.getDiscussionsInPages(forum.id, false, 2).then((response) => {
             if (response.error) {
                 return Promise.reject(null);
             }
@@ -113,8 +115,11 @@ export class AddonModForumPrefetchHandler extends CoreCourseActivityPrefetchHand
             let posts = [];
 
             response.discussions.forEach((discussion) => {
-                promises.push(this.forumProvider.getDiscussionPosts(discussion.discussion).then((ps) => {
-                    posts = posts.concat(ps);
+                promises.push(this.forumProvider.getDiscussionPosts(discussion.discussion).then((response) => {
+                    posts = posts.concat(response.posts);
+
+                    return this.ratingProvider.prefetchRatings('module', forum.cmid, forum.scale, forum.course,
+                            response.ratinginfo);
                 }));
             });
 
@@ -179,7 +184,7 @@ export class AddonModForumPrefetchHandler extends CoreCourseActivityPrefetchHand
         // Get the forum data.
         return this.forumProvider.getForum(courseId, module.id).then((forum) => {
             // Prefetch the posts.
-            return this.getPostsForPrefetch(forum.id).then((posts) => {
+            return this.getPostsForPrefetch(forum).then((posts) => {
                 const promises = [];
 
                 // Prefetch user profiles.
diff --git a/src/addon/mod/forum/providers/sync.ts b/src/addon/mod/forum/providers/sync.ts
index b6fc0559a..b628ce4e0 100644
--- a/src/addon/mod/forum/providers/sync.ts
+++ b/src/addon/mod/forum/providers/sync.ts
@@ -29,6 +29,7 @@ import { CoreUtilsProvider } from '@providers/utils/utils';
 import { AddonModForumProvider } from './forum';
 import { AddonModForumHelperProvider } from './helper';
 import { AddonModForumOfflineProvider } from './offline';
+import { CoreRatingSyncProvider } from '@core/rating/providers/sync';
 
 /**
  * Service to sync forums.
@@ -55,7 +56,8 @@ export class AddonModForumSyncProvider extends CoreSyncBaseProvider {
             private forumProvider: AddonModForumProvider,
             private forumHelper: AddonModForumHelperProvider,
             private forumOffline: AddonModForumOfflineProvider,
-            private logHelper: CoreCourseLogHelperProvider) {
+            private logHelper: CoreCourseLogHelperProvider,
+            private ratingSync: CoreRatingSyncProvider) {
 
         super('AddonModForumSyncProvider', loggerProvider, sitesProvider, appProvider, syncProvider, textUtils, translate,
                 timeUtils);
@@ -135,6 +137,8 @@ export class AddonModForumSyncProvider extends CoreSyncBaseProvider {
             return Promise.all(this.utils.objectToArray(promises));
         }));
 
+        sitePromises.push(this.syncRatings(undefined, undefined, siteId));
+
         return Promise.all(sitePromises);
     }
 
@@ -273,6 +277,50 @@ export class AddonModForumSyncProvider extends CoreSyncBaseProvider {
         return this.addOngoingSync(syncId, syncPromise, siteId);
     }
 
+    /**
+     * Synchronize forum offline ratings.
+     *
+     * @param {number} [cmId] Course module to be synced. If not defined, sync all forums.
+     * @param {number} [discussionId] Discussion id to be synced. If not defined, sync all discussions.
+     * @param {string} [siteId] Site ID. If not defined, current site.
+     * @return {Promise<any>} Promise resolved if sync is successful, rejected otherwise.
+     */
+    syncRatings(cmId?: number, discussionId?: number, siteId?: string): Promise<any> {
+        siteId = siteId || this.sitesProvider.getCurrentSiteId();
+
+        return this.ratingSync.syncRatings('mod_forum', 'post', 'module', cmId, discussionId, siteId).then((results) => {
+            let updated = false;
+            const warnings = [];
+            const promises = [];
+
+            results.forEach((result) => {
+                if (result.updated) {
+                    updated = true;
+
+                    // Invalidate discussions of updated ratings.
+                    promises.push(this.forumProvider.invalidateDiscussionPosts(result.itemSet.itemSetId, siteId));
+                }
+                if (result.warnings.length) {
+                    // Fetch forum to construct the warning message.
+                    promises.push(this.forumProvider.getForum(result.itemSet.courseId, result.itemSet.instanceId, siteId)
+                            .then((forum) => {
+                        result.warnings.forEach((warning) => {
+                            warnings.push(this.translate.instant('core.warningofflinedatadeleted', {
+                                component: this.componentTranslate,
+                                name: forum.name,
+                                error: warning
+                            }));
+                        });
+                    }));
+                }
+            });
+
+            return this.utils.allPromises(promises).then(() => {
+                return { updated, warnings };
+            });
+        });
+    }
+
     /**
      * Synchronize all offline discussion replies of a forum.
      *