diff --git a/common/changes/users-ottost-tooltipDescribedBy_2017-04-26-20-18.json b/common/changes/users-ottost-tooltipDescribedBy_2017-04-26-20-18.json
new file mode 100644
index 00000000000000..7ec465c0d897c6
--- /dev/null
+++ b/common/changes/users-ottost-tooltipDescribedBy_2017-04-26-20-18.json
@@ -0,0 +1,10 @@
+{
+  "changes": [
+    {
+      "packageName": "office-ui-fabric-react",
+      "comment": "Add aria-describedby to tooltiphost component",
+      "type": "patch"
+    }
+  ],
+  "email": "ottost@microsoft.com"
+}
\ No newline at end of file
diff --git a/packages/office-ui-fabric-react/src/components/Tooltip/TooltipHost.tsx b/packages/office-ui-fabric-react/src/components/Tooltip/TooltipHost.tsx
index 06268c7d37a8fb..3bc2f6645cb11f 100644
--- a/packages/office-ui-fabric-react/src/components/Tooltip/TooltipHost.tsx
+++ b/packages/office-ui-fabric-react/src/components/Tooltip/TooltipHost.tsx
@@ -16,6 +16,7 @@ import { TooltipDelay } from './Tooltip.Props';
 
 import * as stylesImport from './TooltipHost.scss';
 const styles: any = stylesImport;
+import { getId } from '@uifabric/utilities';
 
 export interface ITooltipHostState {
   isTooltipVisible?: boolean;
@@ -40,9 +41,9 @@ export class TooltipHost extends BaseComponent<ITooltipHostProps, ITooltipHostSt
 
   // Render
   public render() {
-    const { calloutProps, content, children, directionalHint, delay } = this.props;
+    const { calloutProps, content, children, directionalHint, delay, id } = this.props;
     const { isTooltipVisible } = this.state;
-
+    const tooltipId = id || getId('tooltip');
     return (
       <div
         className={ css('ms-TooltipHost', styles.host) }
@@ -51,10 +52,12 @@ export class TooltipHost extends BaseComponent<ITooltipHostProps, ITooltipHostSt
         { ...{ onBlurCapture: this._onTooltipMouseLeave } }
         onMouseEnter={ this._onTooltipMouseEnter }
         onMouseLeave={ this._onTooltipMouseLeave }
+        aria-describedby={ isTooltipVisible ? tooltipId : undefined }
       >
         { children }
         { isTooltipVisible && (
           <Tooltip
+            id={ tooltipId }
             delay={ delay }
             content={ content }
             targetElement={ this._getTargetElement() }