How many movies have Diane Keaton and Richard S. Castellano acted in together?

They have worked on 3 movies together! Their first movie together was Lovers and Other Strangers (1970) while their highest rated movie together was The Godfather 1901–1959: The Complete Epic (1981). They have not worked together since The Godfather 1901–1959: The Complete Epic (1981). They are most known for their drama films together.