Jean-Paul Belmondo
Arthur Lespinasse

Bourvil
Anatole

David Niven
Colonnel Carol Matthews, aka 'Le Cerveau'

Eli Wallach
Frankie Scannapieco, godfather of the Italian mafia

Silvia Monti
Sofia Scannapieco, Frankie's sister

Raymond Gérôme
Commissioner

Fernand Guiot
Inspector Mazurel, assistant to the commissioner

Jacques Balutin
Inspector Pochet

Jacques Ciron
Inspector Dubœuf

Patrick Préjean
Belgian Sergeant of the armoured car

Robert Dalban
Belgian soldier of the armored car (with a cold)

Raoul Delfosse
Belgian soldier of the armored car

Mario David
Jean-François, antique dealer in Le Havre

Henri Génès
Chief warden of Poissy prison

Yves Barsacq
Warden of Poissy prison

Dominique Zardi
Warden of Poissy prison

Max Montavon
Antique dealer in Le Havre, Jean-François’ partner

Paul Mercey
André, the flooded owner of the 5th floor

Henri Attal
Member of the Colonel's gang

Tommy Duggan
Superintendent Cummings

Sophie Grimaldi
Blonde on the train

Roger Lumont
Boss of the shop

John Rico
Member of the Italian mafia

Pierre Tornade
Belgian Soldier in Armored Car (uncredited)

Micha Bayard
André's Wife (uncredited)

Gérard Hernandez
Policeman in Le Havre (uncredited)