Attached is a sample application that creates a simple QMenu with one QWidgetAction entry in it (this in turn wraps a QPushButton). As you can see, when the QMenu is assigned to the QPushButton the resulting drop down menu is correct, but when the QMenu is associated with the context menu of the QSystemTrayIcon you get an empty drop down. As far as I'm reading through the source, it seems like all that happens (on the x11 version) in the mouseDown event for the QSystemTrayIcon is menu->popup(globalPos), meaning this should be popping up a normal QMenu.