Grégoire Lecomte, the unlucky actor anxious to find a "real job", goes to take a screen test for a role of a killer, but gets to mafiosi by mistake. He takes their don for a producer, and they mistake him for a hitman with whom they had an appointment. Deluded Lecomte signs contract with them. He is supposed to kill gun dealer Otto Krampe at his birthday party in Saint-Tropez by piercing him with a cap of the umbrella with a built-in syringe with potassium cyanide. Lecomte is not aware that it has to be a real murder.
Pierre Richard
as Grégoire Lecomte, acteur à mi-temps, dragueur à plein temps
Valérie Mairesse
as Sylvette, alias Bunny, inspecteur à la D.S.T.
Christine Murillo
as Josyane Leblanc, contractuelle parisienne, régulière de Grégoire
Gérard Jugnot
as Frédo, agent artistique de Grégoire
Gordon Mitchell
as Moskovitz, le tueur à gages
Roger Carel
as Salvatore Bozzoni, couturier et fournisseur de poison
Gert Fröbe
as Otto Krampe, dit La Baleine
Maurice Risch
as Le producteur de Paris
Dominique Lavanant
as Mireille, femme de Frédo, ex-maîtresse de Grégoire
Axelle Abbadie
as Juliette, la fleuriste, ex-femme non divorcée de Grégoire
Yaseen Khan
as Radj Kahn, homme de main de La Baleine
Didier Sauvegrain
as Stanislas Lefort, dit Constantin Patakis, alias Pierre Juvet, dit 'La Folle'
