diff --git a/src/vs/workbench/electron-browser/main.contribution.ts b/src/vs/workbench/electron-browser/main.contribution.ts
index f59f62091d3cd3014088d87fb349316fdd9e017d..2b3c1e55c2209dd13c70a43abe12019485c194e6 100644
--- a/src/vs/workbench/electron-browser/main.contribution.ts
+++ b/src/vs/workbench/electron-browser/main.contribution.ts
@@ -298,6 +298,11 @@ configurationRegistry.registerConfiguration({
 			'default': true,
 			'description': nls.localize('zenMode.hideStatusBar', "Controls if turning on Zen Mode also hides the status bar at the bottom of the workbench.")
 		},
+		'zenMode.hideActivityBar': {
+			'type': 'boolean',
+			'default': true,
+			'description': nls.localize('zenMode.hideActivityBar', "Controls if turning on Zen Mode also hides the activitybar bar at the left of the workbench.")
+		},
 		'zenMode.restore': {
 			'type': 'boolean',
 			'default': false,
diff --git a/src/vs/workbench/electron-browser/workbench.ts b/src/vs/workbench/electron-browser/workbench.ts
index 4b36e94d7518c4ecaae280c978bca5f5cc2acfcc..51b734699fcdceab051e2d89fa085c804f8b4aac 100644
--- a/src/vs/workbench/electron-browser/workbench.ts
+++ b/src/vs/workbench/electron-browser/workbench.ts
@@ -106,6 +106,7 @@ interface WorkbenchParams {
 interface IZenModeSettings {
 	fullScreen: boolean;
 	hideTabs: boolean;
+	hideActivityBar: boolean;
 	hideStatusBar: boolean;
 	restore: boolean;
 }
@@ -1109,7 +1110,10 @@ export class Workbench implements IPartService {
 			this.setPanelHidden(true, true).done(undefined, errors.onUnexpectedError);
 			this.setSideBarHidden(true, true).done(undefined, errors.onUnexpectedError);
 
-			this.setActivityBarHidden(true, true);
+			this.setActivityBarHidden(false, false);
+			if (config.hideActivityBar) {
+				this.setActivityBarHidden(true, true);
+			}
 			if (config.hideStatusBar) {
 				this.setStatusBarHidden(true, true);
 			}