Alain Delon

as Mr. Robert Klein

Jeanne Moreau

as Florence

Francine Bergé

as Nicole

Juliet Berto

as Jeanine, Robert's mistress

Jean Bouise

as Seller of the painting

Suzanne Flon

as Concierge of rue des Abbesses

Massimo Girotti

as Charles, Florence's husband

Michael Lonsdale

as Pierre