diff --git a/javafx-ui-controls/src/com/sun/javafx/scene/control/behavior/MenuButtonBehaviorBase.java b/javafx-ui-controls/src/com/sun/javafx/scene/control/behavior/MenuButtonBehaviorBase.java
--- a/javafx-ui-controls/src/com/sun/javafx/scene/control/behavior/MenuButtonBehaviorBase.java
+++ b/javafx-ui-controls/src/com/sun/javafx/scene/control/behavior/MenuButtonBehaviorBase.java
@@ -38,6 +38,7 @@
 
 import javafx.geometry.Side;
 import javafx.scene.control.MenuButton;
+import javafx.scene.input.MouseButton;
 import javafx.scene.input.MouseEvent;
 
 /**
@@ -153,7 +154,9 @@
             if (control.isShowing()) {
                 control.hide();
             } else {
-                control.show();
+                if( e.getButton() == MouseButton.PRIMARY ) {
+                    control.show();    
+                }
             }
         }
     }