diff --git a/src/vs/workbench/api/browser/mainThreadComments.ts b/src/vs/workbench/api/browser/mainThreadComments.ts
index 3371106e1a5..9a6f866362c 100644
--- a/src/vs/workbench/api/browser/mainThreadComments.ts
+++ b/src/vs/workbench/api/browser/mainThreadComments.ts
@@ -366,6 +366,14 @@ export class MainThreadCommentController {
 		thread.dispose();
 	}
 
+	deleteCommentThreadMain(commentThreadId: string) {
+		this._threads.forEach(thread => {
+			if (thread.threadId === commentThreadId) {
+				this._proxy.$deleteCommentThread(this._handle, thread.commentThreadHandle);
+			}
+		});
+	}
+
 	updateInput(input: string) {
 		let thread = this.activeCommentThread;
 
diff --git a/src/vs/workbench/api/common/extHost.protocol.ts b/src/vs/workbench/api/common/extHost.protocol.ts
index e5a79e59dbb..3386015e6c4 100644
--- a/src/vs/workbench/api/common/extHost.protocol.ts
+++ b/src/vs/workbench/api/common/extHost.protocol.ts
@@ -1210,6 +1210,7 @@ export interface ExtHostCommentsShape {
 	$createNewCommentThread(handle: number, document: UriComponents, range: IRange, text: string): Promise<modes.CommentThread | null>;
 	$createCommentThreadTemplate(commentControllerHandle: number, uriComponents: UriComponents, range: IRange): void;
 	$onCommentWidgetInputChange(commentControllerHandle: number, document: UriComponents, range: IRange, input: string | undefined): Promise<number | undefined>;
+	$deleteCommentThread(commentControllerHandle: number, commentThreadHandle: number): void;
 	$provideCommentingRanges(commentControllerHandle: number, uriComponents: UriComponents, token: CancellationToken): Promise<IRange[] | undefined>;
 	$checkStaticContribution(commentControllerHandle: number): Promise<boolean>;
 	$provideReactionGroup(commentControllerHandle: number): Promise<modes.CommentReaction[] | undefined>;
diff --git a/src/vs/workbench/api/common/extHostComments.ts b/src/vs/workbench/api/common/extHostComments.ts
index fb783e83775..9276ca5f685 100644
--- a/src/vs/workbench/api/common/extHostComments.ts
+++ b/src/vs/workbench/api/common/extHostComments.ts
@@ -173,6 +173,14 @@ export class ExtHostComments implements ExtHostCommentsShape {
 		return Promise.resolve(commentControllerHandle);
 	}
 
+	$deleteCommentThread(commentControllerHandle: number, commentThreadHandle: number) {
+		const commentController = this._commentControllers.get(commentControllerHandle);
+
+		if (commentController) {
+			commentController.$deleteCommentThread(commentThreadHandle);
+		}
+	}
+
 	$provideCommentingRanges(commentControllerHandle: number, uriComponents: UriComponents, token: CancellationToken): Promise<IRange[] | undefined> {
 		const commentController = this._commentControllers.get(commentControllerHandle);
 
@@ -764,6 +772,16 @@ class ExtHostCommentController implements vscode.CommentController {
 		return commentThread;
 	}
 
+	$deleteCommentThread(threadHandle: number) {
+		let thread = this._threads.get(threadHandle);
+
+		if (thread) {
+			thread.dispose();
+		}
+
+		this._threads.delete(threadHandle);
+	}
+
 	$onCommentWidgetInputChange(uriComponents: UriComponents, range: IRange, input: string) {
 		if (!this.inputBox) {
 			this.inputBox = new ExtHostCommentInputBox(this._proxy, this.handle, URI.revive(uriComponents), extHostTypeConverter.Range.to(range), input);
diff --git a/src/vs/workbench/contrib/comments/browser/commentService.ts b/src/vs/workbench/contrib/comments/browser/commentService.ts
index 86ee098d6b2..4823e3aec3a 100644
--- a/src/vs/workbench/contrib/comments/browser/commentService.ts
+++ b/src/vs/workbench/contrib/comments/browser/commentService.ts
@@ -52,6 +52,7 @@ export interface ICommentService {
 	registerDataProvider(owner: string, commentProvider: DocumentCommentProvider): void;
 	unregisterDataProvider(owner: string): void;
 	updateComments(ownerId: string, event: CommentThreadChangedEvent): void;
+	disposeCommentThread(ownerId: string, threadId: string): void;
 	createNewCommentThread(owner: string, resource: URI, range: Range, text: string): Promise<CommentThread | null>;
 	replyToCommentThread(owner: string, resource: URI, range: Range, thread: CommentThread, text: string): Promise<CommentThread | null>;
 	editComment(owner: string, resource: URI, comment: Comment, text: string): Promise<void>;
@@ -144,6 +145,13 @@ export class CommentService extends Disposable implements ICommentService {
 		commentController.createCommentThreadTemplate(resource, range);
 	}
 
+	disposeCommentThread(owner: string, threadId: string) {
+		let controller = this.getCommentController(owner);
+		if (controller) {
+			controller.deleteCommentThreadMain(threadId);
+		}
+	}
+
 	getCommentMenus(owner: string): CommentMenus {
 		if (this._commentMenus.get(owner)) {
 			return this._commentMenus.get(owner)!;
diff --git a/src/vs/workbench/contrib/comments/browser/commentThreadWidget.ts b/src/vs/workbench/contrib/comments/browser/commentThreadWidget.ts
index d9a4fb60eac..03dc6863c89 100644
--- a/src/vs/workbench/contrib/comments/browser/commentThreadWidget.ts
+++ b/src/vs/workbench/contrib/comments/browser/commentThreadWidget.ts
@@ -267,6 +267,7 @@ export class ReviewZoneWidget extends ZoneWidget implements ICommentThreadWidget
 				if (deleteCommand) {
 					return this.commandService.executeCommand(deleteCommand.id, ...(deleteCommand.arguments || []));
 				} else if (this._commentEditor.getValue() === '') {
+					this.commentService.disposeCommentThread(this._owner, this._commentThread.threadId!);
 					this.dispose();
 					return Promise.resolve();
 				}