Italian rock and roll star Adriano Celentano (playing himself) is taking a vacation in the beautiful coastal resort town of Amalfi along with his group, the Rebels, his manager Giovanni (Erminio Marcrio) and his entourage. However, it's not long before they get into a fight at a roadside bar filled with surly local men who regard the rock and rollers as intruders. Things are no better at the hotel. Despite the fawning attention of the manager (Giacomo Furia), the staff are either rude or downright hostile to these outsiders.
Meanwhile, the village idiot Peppino (played by Adriano Celantano in a dual role), who is the dead splitting image of Celentano, is persuaded by a unscrupulous "manager" to pose as the singer in signing autographs and making personal appearances for money at local record shops. Peppino has a recently broke up with his girlfriend, the firey-tempered Carmelina (Claudia Mori) who has recently given birth to his son, which has left her furious. When Celantano is walking on the beach near Carmelina's house, she runs out and attacks him, thinking that he is Peppino. Carmelina threatens the startled celebrity with a shotgun and shoots at him as he runs away. He is lumbered with Carmelina's child, whose paternity he has no knowledge of. He leaves the infant in his hotel room as he goes out to sort his life.
Celantino is trying to impress Emanuela (Donatella Turi) the attractive young daughter of a well-to-do Amalfi resident, Signor Mazzolani (Luigi Pavese), who believes that rock and roll singers are not right for his little girl. No matter how hard Celentano tries to distance himself from the baby, it keeps being accidentally returned to his hotel room. Celantino becomes worried that Emanuela will see him with the baby and mistakenly think he is a philander.
Celantano arranges to perform at a swish club and invites Emanuela and Signor Mazzolani, promising them a more sophisticated evenings musical entertainment. Elsewhere, Peppino's manager has rashly promised a gig on the same night at a coffee shop of devoted female fans. But Peppino makes a run for it. The female fans become furious that Celantano won't show. As Celantano leaves his hotel room for his gig, he is grabbed by aggressive women and take back to their coffee shop to perform for them. Simultaneously, Peppino is bullied into taking over the star's fancy show, and mimes to a Celentano record that his manager plays. Mazzolani is impressed. But when the record sticks, the posh crows realizes that he's a phony and storm the stage, throwing napkins. At the last moment as Peppino flees, Celentano arrives back at the club and calms down the crowd with a rock and roll tango.
On the street, Peppino passes by the hotel where he sees his baby alone through a hotel window. An uproarious farce erupts when Peppino enters room after room unable to located the correct one with his son. The chaos leads to Celentano getting blamed for it when he returns to the hotel. Carmelina arrives and confronts Celentano (thinking that he's Peppino), and a row breaks out in front of Emanuela Mazzolani and her outraged father. But disaster is finally averted when Celentano runs and he and Peppino literally bump into each other and finally meet face-to-face. All becomes clear to everybody as Peppino leaves with Carmelina and the baby, and Celentano goes back to renew his relationship with Emanuela.