Madhvi (Asha Parekh) is an orphan living with her maternal uncle, who arranges her marriage with someone she does not know, so she runs away to her lover, Kailash (Prem Chopra), only to find him in the arms of another woman, Shabnam (Bindu). She then returns to her maternal uncle, only to find him dead. She runs away from there, and later meets a friend, who is a widow and her child at a railway station. The three travel together by train to meet Poonam's in-laws, who have never seen her. Unfortunately, the train meets with an accident, killing the widow, who leaves the child in Madhvi's care. Madhvi assumes the identity of the dead woman, Poonam, and travels along with the child to her in-laws. She is welcomed with open arms. She finds out that her uncle had arranged her marriage with Kamal Sinha (Rajesh Khanna). Kamal is angry and bitter at the manner his to-be wife treated him, even without knowing him. Kamal is attracted to Poonam, but she tries to distance herself, fearing that he will find out the truth about her. Then Shabnam and Kailash re-enter her life, making her look like an imposter, turning her in-laws against her, and turning Kamal's love into resentment.
