 <ul> <li><p>You could expose an event on your mediator so it notifies all listeners (eg your second VM) that its values have changed. .NET has a standard way of doing this: you could implement the <code>INotifyPropertyChanged</code><br> interface:<br> <a href="http://msdn.microsoft.com/en-us/library/vstudio/system.componentmodel.inotifypropertychanged" rel="nofollow">http://msdn.microsoft.com/en-us/library/vstudio/system.componentmodel.inotifypropertychanged</a> </p> <p>An example/tutorial: <a href="http://www.dreamincode.net/forums/topic/208833-using-the-inotifypropertychanged-functionality/" rel="nofollow">http://www.dreamincode.net/forums/topic/208833-using-the-inotifypropertychanged-functionality/</a></p></li> <li><p>The easiest way would be to use a messenger implementation, please<br> read this answer: <a href="http://stackoverflow.com/a/16149579/690178">http://stackoverflow.com/a/16149579/690178</a></p></li> </ul>