The alternative is redesigning your service to use WCF sessions. You can create an operation that is starts the session, while marking others as unable to be called until the 'IsInitializing' operation is called first. Once you understand how WCF sessions work, you'll see they are a very powerful mechanism for controlling the call flow to your service. Generally, parameterized constructors for WCF services is discouraged (see IDesign's WCF Code Standards, great document). You can find out more about WCF sessions here: http://msdn.microsoft.com/en-us/library/ms733040.aspx[^]