How many movies have Larry Hagman and Walter Matthau acted in together?

They have worked on 3 movies together! Their first movie together was Two by Saroyan: 'Once Around the Block' and 'My Heart's in the Highlands' (1960) while their highest rated movie together was Fail Safe (1964). They have not worked together since Fail Safe (1964). They are most known for their comedy films together.