Vittorio De Sica still hadn't found the ideal actor to play Bruno when filming began. It was while he was shooting the scene in which Antonio searches for his friend who can help him locate the bike that fate intervened. "I was telling Maggiorani something," he recalled, "when I turned around in annoyance at the onlookers who were crowding around me, and saw an odd-looking child with a round face, a big funny nose and wonderful lively eyes. Saint Gennaro has sent him to me, I thought. It was proof of the fact that everything was turning out right." And so little Enzo Staiola was hired on the spot to play Bruno.
The movie director Sergio Leone worked as an assistant to Vittorio De Sica during the filming of this movie. He also makes a short appearance as one of the priests that are standing next to Bruno and Antonio during the rainstorm.
For his cast, Vittorio De Sica chose a factory fitter, who had brought his son along for an audition, as his male lead. His leading actress was a journalist who had approached him for an interview, while the young boy was played by a child spotted in the crowd watching the filming.