I think SteveUK is talking about something like this in c++: void foo( const string& text ); According to Programming C# by Jesse Liberty you can pass by reference but I was not able to find anything about passing by const reference: void foo( ref string text ) { ... } The only ways I was able to find on passing parameters are: by-val, by-ref, and with the "out" modifier (which appears to be similar to by-ref.) Hope this helps. jv