Spartaco and Golia, realtives who live in the same building in Rome, often fight with each other, letting their respective families participate. Spartaco has two children, Romano and Silvia, Golia's family consists of his wife, son Paolo and himself. The families should keep the peace because Paolo is in love with Silvia, but their parents try to break their relationship apart. The sons Paolo and Romano are chiefs of two gangs, which don't miss a beat to play tricks on each other. One day, an uncle arrives from the States, together with a lovely girl, Dorothy, who searches for a husband. Spartaco and Serafina try their hardest to make Dorothy fall in love with their sons, but she decides on Giulio, a friend of the family. Silvia misunderstands the situation and believes that Dorothy chose her boyfriend Paolo to be her husband. She is lovesick and runs away from home. Both families search for her. Silvia is finally found and the crisis brought both families closer together.