James Mason as Dr. John Polidori

Leonard Whiting as Victor Frankenstein

David McCallum as Dr. Clervall

Jane Seymour as Agatha / Prima

Nicola Pagett as Elizabeth Fanschawe

Michael Sarrazin as The Creature

Michael Wilding as Sir Richard Fanshawe

Tom Baker as Sea Captain

Clarissa Kaye-Mason as Lady Fanschawe

Agnes Moorehead as Mrs. Blair

Margaret Leighton as Francoise DuVal

Ralph Richardson as Mr. Lacey

John Gielgud as Chief Constable

Peter Sallis as Priest

Yootha Joyce as Hospital Matron

Dallas Adams as Felix

Julian Barnes as Young Man

Karl Howman as William Frankenstein