How many movies have Roddy McDowall and Ron Harper acted in together?

They have worked on 5 movies together! Their first movie together was Back to the Planet of the Apes (1980) while their highest rated movie together was The Forgotten City of the Planet of the Apes (1980). They have not worked together since Farewell to the Planet of the Apes (1980). They are most known for their science fiction films together.