There are two ways of recursively calling lambda functions, neither perfect, but both usable. Func<int,int> fib = null; fib = n => n > 1 ? fib(n - 1) + fib

There are two ways of recursively calling lambda functions, neither perfect, but both usable. Func<int,int> fib = null; fib = n => n > 1 ? fib(n - 1) + fib(n - 2) : n; Or write yourself a Y fixed-point combinator, described in http://blogs.msdn.com/b/wesdyer/archive/2007/02/02/anonymous-recursion-in-c.aspx http://blogs.msdn.com/b/wesdyer/archive/2007/02/02/anonymous... delegate Func<A,R> Recursive<A,R>(Recursive<A,R> r); static Func<A, R> Y<A, R>(Func<Func<A, R>, Func<A, R>> f) { Recursive<A, R> rec = r => a => f(r(r))(a); return rec(rec); } used like this: Func<int,int> fib = Y<int,int>(f => n => n > 1 ? f(n - 1) + f(n - 2) : n); (I'm not advocating writing a fib function this way, but it's a useful example!)