First movie direction for both Steno and Mario Monicelli, who had worked only as screenwriters prior to this movie. Producer Carlo Ponti proposed the direction to them because after a short search he couldn't find another director. After that, they quickly became two of the most important Italian movie directors ever.
Actor Giacomo Furia stated in an interview that he originally had to do only a brief appearance, but then his scene playing Pasquale Saluto at the registry office where Beniamino Lomacchio (Totò) works was totally ad-libbed, making this a cult scene. Giacomo Furia worked then in several movies with Totò.
Producer Carlo Ponti persuaded Totò to take part to a second movie immediately after L'imperatore di Capri (1949), whose filming required less than the 7 weeks initially estimated, so he was free for at least 4 weeks. Ponti asked directors Steno and Mario Monicelli to quickly write down some ideas for a new movie with Totò, and they wrote down this plot together with Agenore Incrocci and Furio Scarpelli, based on the play Il custode of Alfredo Moscariello and Attalo's comics La famiglia Sfollatini. Carlo Ponti commissioned same Steno and Monicelli the direction of the movie.
Some gags were inspired by some short movies of Charlot. The sketch of the stamps is taken from Totò's revue play Orlando curioso (1942), the one of baby Totò from La vile seduttrice (1932).
The square where Beniamino Lomacchio (Totò) drives through during the chase is Piazza San Bernardo in Rome, where also a great scene of Angels and Demons (2009) was shot.