The French title 'Les Barbouzes' uses period French slang for a secret agent or spy, deriving from the notion of spies hiding behind false beards ('barbouze' originally meant a beard, then a fake beard).

The film was shot partly at the Château de Vigny in the Val-d'Oise, France.

The film includes a wink to Georges Lautner's previous hit Les Tontons flingueurs: when the character Cafarelli is introduced, photos are shown of Raoul Volfoni (a character from Les Tontons flingueurs) in embarrassing situations, such as slumped after being punched by Lino Ventura or bandaged in hospital.

A funeral wreath in the film bears Cyrillic text meant to read 'To my dear brother' but actually contains a typographical error, confusing two letters of the Cyrillic alphabet.

Lino Ventura, André Weber and Jess Hahn had already appeared together in a 1957 spy film, Action Immédiate, directed by Maurice Labro.

The film's stunt doubles for the main actors are shown on screen at the very beginning of the movie.

The film's voice-over narration was provided by actor Jean Rochefort, though uncredited.

Released in December 1964, Les Barbouzes drew over 2.4 million admissions in France, including nearly 700,000 in Paris, ranking 16th at the French box office that year and staying in the Parisian weekly top 10 for eight weeks without ever reaching first place.