Eight-year-old Madan is separated from his wealthy parents, Thakur Harcharan Singh (Shivraj) and his wife Rajni. Their other son, Sunil (Dharmendra) grows up to become a police inspector and is searching for his lost brother Madan.
Madan (Shammi Kapoor) — who now is known by the name Shyam — has managed to survive by becoming a petty thief and has ended up in jail. On his release he boards a train to Mumbai, where he meets Shantilal, a man he had known earlier in jail. The man, who is old and ill, asks Shyam to find his two daughters, Sangita and Sushma, whom he had abandoned due to poverty and debt years before.
When Shyam arrives in Mumbai, he begins searching for the sisters. He soon finds a young woman named Sushma (Nishi Kohli). When she drives off, he follows her in a taxi to a theater owned by Harcharan Singh — who arrives with his wife.
Sushma’s sister Sangita (Madhubala) is practicing dance for her stage debut in a play called “Boy Friend.” The problem is that the play does not have a male lead.
While they are at the theater, Mrs. Singh’s necklace is stolen by someone in the crowd. Inspector Sunil has just arrived with his men, and they start chasing the thief. Shyam sees the thief hide the necklace in a case in the sisters’ car. That evening Shyam sneaks into the sisters’ house and retrieves the stolen necklace from the case. He also meets Sangita. When he relays their father’s message to them, the sisters invite him to stay with them.
Shyam leaves early the next morning to return the stolen necklace to Sunil. But the Singhs’ servant Sampat (Dhumal) steals the necklace from him and sells the necklace to a dealer.
Shyam, deciding to leave the life of crime and seek a job, sees the ad for a hero opposite Sangita in “Boy Friend” and goes to audition in front of Harcharan Singh. He is hired and the show opens in Shimla with great success. When he takes Sangita skiing, she breaks her leg - an operation is expensive, and she cannot appear on stage any longer. Harcharan sends his manager to demand that the sisters pay off their debt to him or lose their house. Shyam is furious at this, and quits his job as hero for the theater company. Without a job, the problem is finding the money that Sangita needs desperately without resorting to his old thieving ways.