diff --git a/src/vs/workbench/api/electron-browser/mainThreadComments.ts b/src/vs/workbench/api/electron-browser/mainThreadComments.ts
index 226f8e2367ed9dd7880ee09b4cb7012233bcd0f8..a0bfc4493413924a7930d22aee4df7ef05d9b866 100644
--- a/src/vs/workbench/api/electron-browser/mainThreadComments.ts
+++ b/src/vs/workbench/api/electron-browser/mainThreadComments.ts
@@ -17,6 +17,8 @@ import { IPanelService } from 'vs/workbench/services/panel/common/panelService';
 import { URI } from 'vs/base/common/uri';
 import { ITelemetryService } from 'vs/platform/telemetry/common/telemetry';
 import { generateUuid } from 'vs/base/common/uuid';
+import { IConfigurationService } from 'vs/platform/configuration/common/configuration';
+import { ICommentsConfiguration } from 'vs/workbench/parts/comments/electron-browser/comments.contribution';
 
 export class MainThreadDocumentCommentProvider implements modes.DocumentCommentProvider {
 	private _proxy: ExtHostCommentsShape;
@@ -72,18 +74,18 @@ export class MainThreadComments extends Disposable implements MainThreadComments
 	private _documentProviders = new Map<number, IDisposable>();
 	private _workspaceProviders = new Map<number, IDisposable>();
 	private _handlers = new Map<number, string>();
-	private _firstSessionStart: boolean;
+	private _openPanelListener: IDisposable | null;
 
 	constructor(
 		extHostContext: IExtHostContext,
 		@IEditorService private _editorService: IEditorService,
 		@ICommentService private _commentService: ICommentService,
 		@IPanelService private _panelService: IPanelService,
-		@ITelemetryService private _telemetryService: ITelemetryService
+		@ITelemetryService private _telemetryService: ITelemetryService,
+		@IConfigurationService private _configurationService: IConfigurationService
 	) {
 		super();
 		this._disposables = [];
-		this._firstSessionStart = true;
 		this._proxy = extHostContext.getProxy(ExtHostContext.ExtHostComments);
 	}
 
@@ -97,19 +99,62 @@ export class MainThreadComments extends Disposable implements MainThreadComments
 		this._commentService.registerDataProvider(providerId, handler);
 	}
 
+	/**
+	 * If the comments panel has never been opened, the constructor for it has not yet run so it has
+	 * no listeners for comment threads being set or updated. Listen for the panel opening for the
+	 * first time and send it comments then.
+	 */
+	private registerOpenPanelListener(commentsPanelAlreadyConstructed: boolean) {
+		if (!commentsPanelAlreadyConstructed && !this._openPanelListener) {
+			this._openPanelListener = this._panelService.onDidPanelOpen(e => {
+				if (e.panel.getId() === COMMENTS_PANEL_ID) {
+					keys(this._workspaceProviders).forEach(handle => {
+						this._proxy.$provideWorkspaceComments(handle).then(commentThreads => {
+							if (commentThreads) {
+								const providerId = this._handlers.get(handle);
+								this._commentService.setWorkspaceComments(providerId, commentThreads);
+							}
+
+						});
+					});
+
+					this._openPanelListener.dispose();
+					this._openPanelListener = null;
+				}
+			});
+		}
+	}
+
 	$registerWorkspaceCommentProvider(handle: number, extensionId: string): void {
 		this._workspaceProviders.set(handle, undefined);
 
 		const providerId = generateUuid();
 		this._handlers.set(handle, providerId);
 
+		const commentsPanelAlreadyConstructed = this._panelService.getPanels().some(panel => panel.id === COMMENTS_PANEL_ID);
 		this._panelService.setPanelEnablement(COMMENTS_PANEL_ID, true);
-		if (this._firstSessionStart) {
+
+		const openPanel = this._configurationService.getValue<ICommentsConfiguration>('comments').openPanel;
+
+
+		if (openPanel === 'neverOpen') {
+			this.registerOpenPanelListener(commentsPanelAlreadyConstructed);
+		}
+
+		if (openPanel === 'openOnSessionStart') {
 			this._panelService.openPanel(COMMENTS_PANEL_ID);
-			this._firstSessionStart = false;
 		}
+
 		this._proxy.$provideWorkspaceComments(handle).then(commentThreads => {
 			if (commentThreads) {
+				if (openPanel === 'openOnSessionStartWithComments' && commentThreads.length) {
+					if (commentThreads.length) {
+						this._panelService.openPanel(COMMENTS_PANEL_ID);
+					} else {
+						this.registerOpenPanelListener(commentsPanelAlreadyConstructed);
+					}
+				}
+
 				this._commentService.setWorkspaceComments(providerId, commentThreads);
 			}
 		});
@@ -135,7 +180,13 @@ export class MainThreadComments extends Disposable implements MainThreadComments
 		this._workspaceProviders.delete(handle);
 		if (this._workspaceProviders.size === 0) {
 			this._panelService.setPanelEnablement(COMMENTS_PANEL_ID, false);
+
+			if (this._openPanelListener) {
+				this._openPanelListener.dispose();
+				this._openPanelListener = null;
+			}
 		}
+
 		const handlerId = this._handlers.get(handle);
 		this._commentService.removeWorkspaceComments(handlerId);
 		this._handlers.delete(handle);
diff --git a/src/vs/workbench/parts/comments/electron-browser/comments.contribution.ts b/src/vs/workbench/parts/comments/electron-browser/comments.contribution.ts
index 9698f7ec05ce12c50d44d156f73611cc84c1ae75..0fa4480285884909a6609659d534f85ad61e04bd 100644
--- a/src/vs/workbench/parts/comments/electron-browser/comments.contribution.ts
+++ b/src/vs/workbench/parts/comments/electron-browser/comments.contribution.ts
@@ -3,6 +3,7 @@
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
 
+import * as nls from 'vs/nls';
 import { LifecyclePhase } from 'vs/platform/lifecycle/common/lifecycle';
 import { registerSingleton } from 'vs/platform/instantiation/common/extensions';
 import { Registry } from 'vs/platform/registry/common/platform';
@@ -12,6 +13,11 @@ import { IPanelService } from 'vs/workbench/services/panel/common/panelService';
 import { COMMENTS_PANEL_ID, COMMENTS_PANEL_TITLE, CommentsPanel } from './commentsPanel';
 import 'vs/workbench/parts/comments/electron-browser/commentsEditorContribution';
 import { ICommentService, CommentService } from 'vs/workbench/parts/comments/electron-browser/commentService';
+import { IConfigurationRegistry, Extensions as ConfigurationExtensions } from 'vs/platform/configuration/common/configurationRegistry';
+
+export interface ICommentsConfiguration {
+	openPanel: 'neverOpen' | 'openOnSessionStart' | 'openOnSessionStartWithComments';
+}
 
 export class CommentPanelVisibilityUpdater implements IWorkbenchContribution {
 
@@ -35,6 +41,21 @@ Registry.as<PanelRegistry>(PanelExtensions.Panels).registerPanel(new PanelDescri
 	10
 ));
 
+
+Registry.as<IConfigurationRegistry>(ConfigurationExtensions.Configuration).registerConfiguration({
+	id: 'comments',
+	order: 20,
+	title: nls.localize('commentsConfigurationTitle', "Comments"),
+	type: 'object',
+	properties: {
+		'comments.openPanel': {
+			enum: ['neverOpen', 'openOnSessionStart', 'openOnSessionStartWithComments'],
+			default: 'openOnSessionStartWithComments',
+			description: nls.localize('openComments', "Controls when the comments panel should open.")
+		}
+	}
+});
+
 // Register view location updater
 Registry.as<IWorkbenchContributionsRegistry>(WorkbenchExtensions.Workbench).registerWorkbenchContribution(CommentPanelVisibilityUpdater, LifecyclePhase.Starting);
 
diff --git a/src/vs/workbench/parts/preferences/browser/settingsLayout.ts b/src/vs/workbench/parts/preferences/browser/settingsLayout.ts
index 2dc95fd5a3c234613ec2594c3bb322712f0be1a2..f1032c37261a1c53f1a3fefc6b528c1146d1eff4 100644
--- a/src/vs/workbench/parts/preferences/browser/settingsLayout.ts
+++ b/src/vs/workbench/parts/preferences/browser/settingsLayout.ts
@@ -154,6 +154,11 @@ export const tocData: ITOCEntry = {
 					id: 'features/problems',
 					label: localize('problems', "Problems"),
 					settings: ['problems.*']
+				},
+				{
+					id: 'features/comments',
+					label: localize('comments', "Comments"),
+					settings: ['comments.*']
 				}
 			]
 		},