diff --git a/common/changes/office-ui-fabric-react/splitbuttonMeny_2018-02-21-18-32.json b/common/changes/office-ui-fabric-react/splitbuttonMeny_2018-02-21-18-32.json
new file mode 100644
index 0000000000000..baf153dc41b31
--- /dev/null
+++ b/common/changes/office-ui-fabric-react/splitbuttonMeny_2018-02-21-18-32.json
@@ -0,0 +1,11 @@
+{
+  "changes": [
+    {
+      "packageName": "office-ui-fabric-react",
+      "comment": "Contextual Menu - Added aria-posinset and aria-setsize to split buttons",
+      "type": "patch"
+    }
+  ],
+  "packageName": "office-ui-fabric-react",
+  "email": "chiechan@microsoft.com"
+}
\ No newline at end of file
diff --git a/packages/office-ui-fabric-react/src/components/ContextualMenu/ContextualMenu.tsx b/packages/office-ui-fabric-react/src/components/ContextualMenu/ContextualMenu.tsx
index 0bbdc7a0a6242..c935ee44753f1 100644
--- a/packages/office-ui-fabric-react/src/components/ContextualMenu/ContextualMenu.tsx
+++ b/packages/office-ui-fabric-react/src/components/ContextualMenu/ContextualMenu.tsx
@@ -558,6 +558,8 @@ export class ContextualMenu extends BaseComponent<IContextualMenuProps, IContext
         aria-haspopup={ true }
         aria-describedby={ item.ariaDescription }
         aria-checked={ item.isChecked || item.checked }
+        aria-posinset={ focusableElementIndex + 1 }
+        aria-setsize={ totalItemCount }
       >
         <span
           aria-hidden={ true }