I assume these are cs, not cls files ? Their names don't really matter, but it all sounds very convoluted. What's the problem you're having ? You just want to pass parameters from class to class ? If you posted some code, perhaps we could get an idea of what's going on ? Is all this stuff irrelevant, and your problem is just how to call a stored proc from C# ? If so, I answered that question below earlier today. Christian Graus - Microsoft MVP - C++