Sanjay (Rajendra Kumar) is in love with Priya (Saira Banu). They are painting rosy dreams of their life as husband and wife, until Priya learns that her father has been arrested. The duo decide that they will get married after Priya is able to bail out her father. Sanjay is happy, but destiny has other plans: Sanjay dies in a car crash. But after he is escorted by an angel (David) to heaven, he learns that his death was a mistake.

The angel makes arrangements to send Sanjay back to earth, but his body has already been cremated. Then, the angel takes him to the house of Tarun Kumar, Sanjay's lookalike, who should have been originally killed instead of Sanjay. Tarun has been murdered just seconds before by his own brother (Prem Chopra). Sanjay learns that Tarun is a criminal and his brother wants to usurp his money. Now, it is up to Sanjay and his guardian to turn the tides and make up the loss.

Sanjay is a poor man making his living as a tourist guide in Darjeeling. He meets Priya Khanna, who has come from Calcutta. The duo fall in love. Everything is hunky dory for them, until Priya receives the news of her father's arrest. The duo decide to put their dreams on the hold until Priya's father is exonerated. Priya leaves, while Sanjay returns, hopeful and joyous. However, he dies in a car accident and is escorted by an angel for the retribution of his sins.

It is revealed that Sanjay was never supposed to die. The angel learns that he mistakenly killed Sanjay instead of his look alike, Tarun Kumar. As punishment, the angel is tasked with sending Sanjay back to Earth. On Earth, Sanjay's body has already been cremated. Realizing that now Sanjay's soul has to be put in somebody else's body, the angel takes him to Tarun's home. Unknown to them, Tarun has been shot in the back by his own brother mere seconds ago. The angel retrieves the bullet and tells Sanjay to occupy Tarun's body.

Priya succeeds in bailing out her father and learns from him that he was framed by Tarun. Meanwhile, Sanjay learns that Tarun was a criminal and correctly deduces that he was killed for his money. Tarun's errant ways have dissociated him from his grandmother, his only living relative. Sanjay decides to right Tarun's wrongs. Tarun's brother is shocked to see him alive, but Sanjay feigns ignorance. Tarun's secretary Rita is working for his brother secretly. Here, Priya comes back to exact revenge on Tarun, but is obviously stunned to see him.

Sanjay is saddened by the turn of events. He succeeds in convincing his friend (Rajendra Nath) about his true identity. Later, he slowly starts shutting Tarun's illegitimate businesses and diverts the money to charity instead. This sudden change stuns and surprises Tarun's grandmother, while his brother is angered at losing money to this newfound philanthropy. Sanjay starts courting Priya again. Seeing that Tarun has reformed, everybody gives him their blessing to his marriage with Priya. However, Rita drops a bombshell that she is married to Tarun.

Sanjay is unable to prove or disprove anything, making matters worse for him again. However, Rita is acting as a mere pawn in the hands of Tarun's brother. He decides to confront Rita to know the truth, but Tarun's brother has already anticipated it. He kills Rita and Priya is framed for the murder. Sanjay succeeds in running away and confronting Tarun's brother. Tarun's brother finally confesses all his crimes in front of Sanjay, which is also heard by Sanjay's buddy. Just as Sanjay is going to be killed by Tarun's brother, the angel knocks him out.

In the end, Tarun's brother is arrested on the basis of his testimony. Realizing that Sanjay will now be able to live the life in form of Tarun, the very life that was unjustly taken from him, the angel unites him with Priya and returns to his heavenly abode.

The song "Kaun Hai Jo Sapnon Mein Aaya" was inspired from Elvis Presley's "Marguerita" from Fun in Acapulco album.