 <p>The <code>DataContext</code> on your usercontrol isn't set. Specify a <code>Name</code> for it (I usually call mine "ThisControl") and modify the TextBox's binding to <code>Text="{Binding ElementName=ThisControl, Path=TitleValue, Mode=TwoWay}"</code>. You can also set the <code>DataContext</code> explicitly, but I believe this is the preferred way.</p> <p>It seems like the default DataContext should be "this", but by default, it's nothing.</p> <p>[edit] You may also want to add <code>, UpdateSourceTrigger=PropertyChanged</code> to your binding, as by default TextBoxes' Text binding only updates when focus is lost.</p>