Patrick Dempsey

Robert 'Bobby' Libner

Arye Gross

Buddy Libner

Daniel Stern

Marvin Libner

Annabeth Gish

Tammy

Rita Taggart

Betty Libner

Joseph Bologna

Uncle Phil

Alan Arkin

Fred Libner

James Gammon

Dr. Sturgeon The Cadillac Surgeon

Ray Lykins

Rick

John Considine

Professor Kloppner, Eastbrook Academy

Fred Ornstein

Barney

Edan Gross

Young Bobby

Dean Jacobson

Young Marvin

Judi Durand

Additional Voices (voice)

David McCharen

Additional Voices (voice)

Larry Moss

Additional Voices (voice)

Randy Herman

Dog Track Gambler (uncredited)