Virna Lisi

Nathalie Revent

Helmut Berger

Alain Revent

Charles Aznavour

Inspector Leroy

Alain Noury

Dino

Françoise Brion

Jacqueline

Édith Scob

Sylvie Revent

Marc Cassot

Vincent

Yves Brainville

Commissioner Dedru

Henri Crémieux

Professor Richet, psychiatrist

André Chanu

Doctor Schwartz

Georges Berthomieu

Toxicologist

Guy Marly

Chemist

Michel Peyrelon

Maître d'hôtel

Robert Le Béal

Judge

Dominique Marcas

Neighbor

Howard Vernon

Maître Wasserman, property administrator

Nicole Gobbi

Jocelyne Jeanssen

Robert Audran

Paul Pavel

Delivery man

Robert Berri

Alain's concierge

Serge Berry

Paul Bonifas

Hotel porter

Elisabetta Fanti

Alberto Farnese

Alain's friend

Monique Mélinand

Neighbor witness

Roger Coggio

Alain Revent (voice)

Jacques Castelot

(uncredited)

Jacques Chevalier

Police inspector (uncredited)