John Travolta

James

Kirstie Alley

Mollie

Olympia Dukakis

Rosie

George Segal

Albert

Abe Vigoda

Grandpa

Bruce Willis

Mikey (voice)

Twink Caplan

Rona

Joy Boushel

Melissa

Don S. Davis

Dr. Fleischer

Brenda Crichlow

Secretary

Alex Bruhanski

Street Worker

Aurelio Dinunzio

Orderly

William B. Davis

Drug Doctor

Jerry Wasserman

Mr. Anal

Nicholas Rice

Harry

Neal Israel

Mr. Ross

Blu Mankuma

Director

Dee Jay Jackson

Burly Orderly

Mollie Heckerling

Little Girl

Gerry Bean

Pilot Friend

Deryl Hayes

Pilot Friend

Enid Saunders

Ester

Joan Rivers

Julie (voice) (uncredited)