Jeremy Spenser

as Guido Ferugia

Guy Rolfe

as John Morell

Kathleen Ryan

as Catherine Morell

Kathleen Byron

as Anne Bondini

Henry Oscar

as Mario Bondini

Rosalie Crutchley

as Carlotta Ferugia

Ferdy Mayne

as Carlo Ferugia

James Robertson Justice

as Sir Arthur Harold

John Slater

as Dr. Lorenzo

Christopher Lee

as Newsman

Hugo Schuster

as Dr. Freihaus

Robert Rietti

as Giuseppe

Robin Dowell

as Nick Morell

Michael Balfour

as Lucio

David McCallum Sr.

as Leader of orchestra, Royal Albert Hall

Dora Hyde

as Leader of orchestra, Naples

Michael Croudson

as Nick's Friend

Don Liddel

as Benjamino

Ben Willian

as Car Driver

Alex Fields

as Doorkeeper

Penny Dane

as Maid

Leonard Trolley

as Waiter