How many movies have David McCallum and Robert Vaughn acted in together?

They have worked on 9 movies together! Their first movie together was To Trap a Spy (1964) while their highest rated movie together was The Spy in the Green Hat (1967). They have not worked together since The Return of the Man from U.N.C.L.E.: The Fifteen Years Later Affair (1983). They are most known for their adventure films together.