Robert Redford as John Dortmunder

George Segal as Andrew Kelp

Ron Leibman as Stanley Murch

Paul Sand as Alan Greenburg

Moses Gunn as Dr. Amusa

William Redfield as Lt. Hoover

Topo Swope as "Sis" Clara Kelp

Charlotte Rae as Ma Murch

Graham Jarvis as Frank, the Prison Warden

Christopher Guest as Policeman

Zero Mostel as Abe Greenberg

Harry Bellaver as Rollo the Bartender

Seth Allen as Happy Hippie

Robert Levine as Cop At Police Station

Gilbert Lewis as Museum Guard

Ed Bernard as Policeman