Chris Hammond (Kirk Cameron) is a typical high-school senior pursuing his general education: girls, cars and music. His father, Dr. Jack Hammond (Dudley Moore), is a successful heart surgeon, on the verge of being named Chief of Staff at a leading hospital. They're about as close as a father and son can get...but they're about to come even closer. In one split second, father and son accidentally change bodies, resulting in a chaotic change of lifestyle for both of them. The son gets the Jaguar, the gold card and the boss's wife. His father gets the allowance, the biology final and the fake ID!