Patty Duke
— Anna Marie Duke/ Patty Duke
Timothy Carhart
— Harry
Howard Hesseman
— John Ross
Deborah May
— Ethel Ross
Ari Meyers
— Patty Duke, as a youth
Millie Perkins
— Frances Duke
Jenny Robertson
— Patty, as a young adult
Arthur Taxier
— John Astin
Matthew Perry
— Desi Arnaz Jr.
Ray Duke
— John Patrick Duke
Karl Malden
— Doctor Harold Arlen