Christopher Lee as Prof. Sir Alexander Saxton

Peter Cushing as Dr. Wells

Telly Savalas as Captain Kazan

Alberto de Mendoza as Father Pujardov

Silvia Tortosa as Countess Irina Petrovska

Julio Peña as Inspector Mirov

Ángel del Pozo as Yevtushenko

Helga Liné as Natasha

Alice Reinheart as Miss Jones

José Jaspe as Conductor Koniev

George Rigaud as Count Maryan Petrovski

Víctor Israel as Luggage Worker

Faith Clift as American Passenger, Miss Bennett (uncredited)

Juan Olaguibel as Creature

José Marco as Vorkin

José Canalejas as Russian Guard

Vicente Roca as Station Master

Hiroshi Kitatawa as Grashinski - the Locksmith (uncredited)

Barta Barri as First Telegraphist

Peter Beckman as Second Telegraphist (uncredited)

Allen Russell as Capt. O'Hagan (uncredited)

Fernando Villena as (uncredited)

Robert Rietti as Father Pujardov (voice)

Olive Gregg as Countess Irina Petrovski / Natasha / Miss Jones (voice)

Roger Delgado as Inspector Mirov (voice)