At a New York theater, entertainers Joe Anthony and Harvey Miller, Jr. greet their enthusiastic fans and then start their show. In the wings, magazine writer Lorelei Larson listens as Joe's father describes how Joe and Harvey got into show business: As a young man, Harvey struggles to follow in the footsteps of his father, a professional golfer, but is too shy to play in front of onlookers. Joe, meanwhile, refuses to become a San Francisco fisherman like his father and strikes out on his own, but four years later, still has not found his niche. Harvey ends up working at a department store with Joe's sister Lisa, who is also his fiancee. Harvey talks Lisa into attending a golf match with him during their lunch break, and when they return to work three hours late, their boss confronts them. Distraught, the bumbling Harvey wrecks the store, and both he and Lisa are fired. While the two walk home, Lisa cheers Harvey up by suggesting that he open a golf school. Joe, meanwhile, has hitchhiked his way back to San Francisco and is startled to discover Harvey, who is renting Joe's old room, in his bed. Joe tries to evict the sleeping Harvey, until Lisa introduces him as her future husband. The next day, while Harvey practices teeing off on the Anthonys' rooftop, Joe takes a few swings himself, impressing Harvey with his form. Harvey persuades Joe to enter the Santa Barbara Open golf tournament, with Harvey as his caddy. Joe's parents are dismayed by the news, however, as Papa, thinking that his son has returned home to work with him, has borrowed $500 from Mr. Spezzato to buy a new fishing boat. To help pay off his father's debt, Joe trains hard with Harvey and enters the tournament. At the country club where the tournament is being held, Joe is met with suspicion by the snobbish members and Harvey is snubbed and sent off with the other caddies. While Joe is busy impressing socialite Kathy Taylor, Harvey is teased and tricked by the other caddies and winds up half-naked in the country club lobby. Despite their inauspicious start, Joe has a good first day on the tournament, and Harvey prepares a celebratory dinner in their motel room. When Joe announces that he is spending the evening at a club with Kathy, Harvey is crushed but dutifully orders Joe to be back by eleven. Joe fails to return on time, so Harvey marches to the club and interrupts Joe's crooning to retrieve him. The next day, Joe wins the tournament but is compelled to donate the $500 prize to charity. Joe's disappointment is softened when he receives a free suit, golf balls and suitcase from some Santa Barbara businessmen. Decked out in his new suit, Joe tells Harvey that he is going to the Taylor estate in Monterey. When Kathy then drives up, Joe talks Harvey into giving him most of their money and leaves Harvey to fend for himself. Determined to keep Joe in shape, Harvey hitchhikes to the Taylors' with Joe's golf clubs. After sneaking past the Taylors' guard dogs and spending the night in the stable, Harvey finds a discarded robe and ascot and pretends to be a sophisticate in order to get some breakfast. Joe and Kathy then discover him, and Kathy's mother Grace suggests that Harvey be hired as a servant. During a party that night, Harvey receives a phone call from Lisa, who informs him that Spezzato is threatening to take Papa's boat and Mama's restaurant. To keep Joe from over-indulging, Harvey steals all of his cocktails and soon is drunk. After causing a commotion, Harvey tries to tell Joe about Lisa's call, and Kathy assumes that Harvey's reference to Joe as his future brother-in-law means that Lisa is Joe's fiancee. Kathy upbraids Joe and storms off, but later, Harvey explains the situation to her. When she then discovers that Joe has left, she sends some police officers to pick him up on the highway. Having been told that Joe is a thief, the police drag him back to the Taylors'. There, Kathy and Harvey, who is posing as Kathy's cousin, convince the police to free Joe, but Joe is still angry and leaves. The next day, at the Monterey Invitational, in which Joe is scheduled to appear, Kathy gets a call from Joe, who was arrested again on the road. Kathy straightens matters out with the police, and after Harvey stalls the match, Joe arrives in time to enter. When the Anthonys and their friends drive up on the course, however, a free-for-all erupts. In the midst of the melee, Eddie Lear, a theatrical agent who has witnessed all of Joe and Harvey's antics, suggests that they pursue a career in show business. Joe and Harvey perform their first show at Mama's restaurant and are a hit. Back in the present, Papa concludes his tale, while Joe and Harvey finish their show. Waiting to go on next are entertainers Jerry Lewis and Dean Martin, who are mistaken for Joe and Harvey by Kathy and Lisa and given big kisses. Joe and Harvey then appear and confront their baffled look-alikes.