The CommandArgument value of RadButton is not available in the ClientClicking eventargs of RadButton. The get_commandName() method of the event arguments always returns null. The issue is introduced in Q1 2016 release. Steps to reproduce: Run the following code and click the button. <script type="text/javascript"> function btnEdit_Clicking(sender, eventArgs) { alert(eventArgs.get_commandArgument()); } </script> <telerik:RadButton ID="RadButton2" AutoPostBack="false" runat="server" Text="Click Me" OnClientClicking="btnEdit_Clicking" CommandArgument="Name"> </telerik:RadButton>