Hi, I have a customcontrol exposing a Dependency property of type ObservableCollection. When i bind this properrty directly as part ofthe control's mark up in hte containing control everythihng works fine /< temp:EnhancedTextBox CollectionProperty="{Binding Path=MyCollection, Mode=TwoWay}"/ But when i try to do the binding in the style created for the control it fails, /< Style x:Key="abc2" TargetType="{x:Type temp:EnhancedTextBox}" <Setter Property="CollectionProperty" Value="{Binding Path=MyCollection, Mode=TwoWay}"/> Please help !!!!! Thanks