Paul Massie as Dr. Jekyll / Mr. Hyde

Dawn Addams as Kitty Jekyll

Christopher Lee as Paul Allen

David Kossoff as Dr. Littauer

Norma Marla as Maria

Francis de Wolff as Inspector

Joy Webster as Jenny

Magda Miller as Sphinx Girl (uncredited)

Oliver Reed as Nightclub Bouncer (uncredited)

Helen Goss as Nanny (uncredited)

Arthur Lovegrove as Cabby (uncredited)

Walter Gotell as Heverton - Second Gambler (uncredited)

Percy Cartwright as Coroner (uncredited)

John Bonney as Renfrew (uncredited)

Denis Cleary as Waiter (uncredited)

Doug Robinson as Boxer (uncredited)

Fred Stone as Cabinet Minister (uncredited)

Mackenzie Ward as Business Man (uncredited)

Rodney Burke as Young Blood (uncredited)