diff --git a/common/changes/office-ui-fabric-react/no-dismiss-callout_2018-06-04-21-44.json b/common/changes/office-ui-fabric-react/no-dismiss-callout_2018-06-04-21-44.json
new file mode 100644
index 00000000000000..4cfb771e03fb70
--- /dev/null
+++ b/common/changes/office-ui-fabric-react/no-dismiss-callout_2018-06-04-21-44.json
@@ -0,0 +1,11 @@
+{
+  "changes": [
+    {
+      "packageName": "office-ui-fabric-react",
+      "comment": "Callout: Add `preventDismissOnLostFocus` prop.",
+      "type": "minor"
+    }
+  ],
+  "packageName": "office-ui-fabric-react",
+  "email": "jetao@microsoft.com"
+}
diff --git a/packages/office-ui-fabric-react/src/components/Callout/Callout.types.ts b/packages/office-ui-fabric-react/src/components/Callout/Callout.types.ts
index bedfebac1a9610..202667eb5332d2 100644
--- a/packages/office-ui-fabric-react/src/components/Callout/Callout.types.ts
+++ b/packages/office-ui-fabric-react/src/components/Callout/Callout.types.ts
@@ -92,11 +92,17 @@ export interface ICalloutProps {
   isBeakVisible?: boolean;
 
   /**
-   * If true then the onClose will not not dismiss on scroll
+   * If true then the callout will not dismiss on scroll
    * @default false
    */
   preventDismissOnScroll?: boolean;
 
+  /**
+   * If true then the callout will not dismiss when it loses focus
+   * @default false
+   */
+  preventDismissOnLostFocus?: boolean;
+
   /**
    * If true the position returned will have the menu element cover the target.
    * If false then it will position next to the target;
diff --git a/packages/office-ui-fabric-react/src/components/Callout/CalloutContent.base.tsx b/packages/office-ui-fabric-react/src/components/Callout/CalloutContent.base.tsx
index 4e3f9e540c3c52..c65849619a8853 100644
--- a/packages/office-ui-fabric-react/src/components/Callout/CalloutContent.base.tsx
+++ b/packages/office-ui-fabric-react/src/components/Callout/CalloutContent.base.tsx
@@ -58,6 +58,7 @@ export interface ICalloutState {
 export class CalloutContentBase extends BaseComponent<ICalloutProps, ICalloutState> {
 
   public static defaultProps = {
+    preventDismissOnLostFocus: false,
     preventDismissOnScroll: false,
     isBeakVisible: true,
     beakWidth: 16,
@@ -253,13 +254,15 @@ export class CalloutContentBase extends BaseComponent<ICalloutProps, ICalloutSta
   protected _dismissOnLostFocus(ev: Event) {
     const target = ev.target as HTMLElement;
     const clickedOutsideCallout = this._hostElement.current && !elementContains(this._hostElement.current, target);
+    const { preventDismissOnLostFocus } = this.props;
 
     if (
-      (!this._target && clickedOutsideCallout) ||
+      !preventDismissOnLostFocus &&
+      ((!this._target && clickedOutsideCallout) ||
       ev.target !== this._targetWindow &&
       clickedOutsideCallout &&
       ((this._target as MouseEvent).stopPropagation ||
-        (!this._target || (target !== this._target && !elementContains(this._target as HTMLElement, target))))) {
+        (!this._target || (target !== this._target && !elementContains(this._target as HTMLElement, target)))))) {
       this.dismiss(ev);
     }
   }