If you create a templated server control, import it into your web-site or web application and you want to do: <my:Control ID=”myControl” runat=”server”> <ItemTemplate> Some text, html or whatever. </ItemTemplate> </myControl> and you are allowed to do only: <my:Control ID=”myControl” runat=”server” /> you need to modify your ItemTemplate property to look like this: [TemplateContainer(typeof(MyTemplateControl))] [Browsable(false)] […]