This is the first and only film for non-actor Carlo Battisti, who plays the leading role in the film. His real occupation was that of a Professor of Linguistics at the Università degli Studi di Firenze.
Non-actress Maria Pia Casilio, who plays the role of the house maid in the film, got the part when she accompanied a friend to see the real actresses competing for the film's audition. Director Vittorio De Sica spotted her in the balcony and knew she was exactly what he was looking for in the role. Maria went on to work with De Sica in three other films. She continued to work in films until the late 1990s.
Many in the film's cast were new to acting, including Carlo Battisti and Maria Pia Casilio, the two principal actors. Others, including Umberto's cruel landlady, Antonia (Lina Gennari), were established professional actors.
There are two dogs used in the film. The trained one has a black head and its right side is white. Another dog, with a white muzzle and a black spot on its right flank, is used in two scenes - firstly, when Umberto is hiding from the police after the demonstration and, secondly, when he reclaims Flike from the pound.