Elizabeth Montgomery

as Katherine Merrill

Anthony Hopkins

as Dr. Michael Grant

Michele Lee

as Dolores Marsh

Janet MacLachlan

as Eileen

Michael Lerner

as Manny

John Elerick

as Jeremy

Herbert Berghof

as Dr. Kassiter

Vic Tayback

as Archie

Mario Roccuzzo

as Sandy

Julie Rogers

as Veronica

Edgar Daniels

as Zalenki

James Ingersoll

as Dr. Snyder

Jack Manning

as Sam

Garrick Russell

as Eileen's Son

Eric Server

as Dr. Birney

Deborah White

as Janet

Michael Thoma

as Sid (uncredited)