Gloria Guida as Polly

Leonard Mann as Paul De Revere

Joseph Cotten as Sir Arthur Dundee

Adolfo Celi as Sir Harold Boyd

Anthony Steel as Supt. Jeff Hawks

Janet Ågren as Lady Gloria Boyd

Alida Valli as Lady Clementine De Revere

Franco Ressel as Sgt. Phillips

Paul Müller as Gibson

Mario Novelli as Saboteur

Elio Stefanizzi as

Claudio Gora as

Giuseppe Marrocco as Waiter

Attilio Pelegatti as Policeman

Kenneth Benda as Old Gentleman (uncredited)

Tom Felleghy as Dr. Hobbes (uncredited)

Antonio Maimone as Brooks (uncredited)

Filippo Perego as Sir Arthur's Butler (uncredited)

Maria Tedeschi as Lady Clementine's Friend (uncredited)