Richard O'Sullivan

Roger Court

Alida Valli

Roberta Gleukovitch

Eduardo Ciannelli

Dr. Vivaldi

Trevor Howard

Major Roger Court

Richard Basehart

Joe Hamstringer

Stephen Murray

British Consul in Venice

Arnoldo Foà

Commissioner

Guido Celano

Chief Constable

Helen Goss

Undetermined Role

Giorgio Costantini

Pescovitch