A film based on the principle of honesty and truth, Haseena Maan Jayegi is a story about two lookalike men Kamal and Rakesh and their love interest Archana.
Mahavir goes to visit his old friend Randhir after ages. Mahavir has just admitted his daughter Archana to college and Randhir’s son Rakesh is a researcher. Rakesh is a popular man in college and has a couple of loyal followers. When he is told that there is a new girl I college who will not fall prey to his charms easily, Rakesh readily takes on the challenge. He follows Archana around and tries to woo her, which results in Archana being convinced of his being a nuisance. Tired of being harassed by Rakesh, she complains to the Principal. Unfortunately, when told to identify the culprit, she points to Kamal, who looks exactly like Rakesh.
Realizing her mistake, Archana feels guilty and insists on making it up to Kamal. She drops him off after university and as they spend time together, the two fall in love. When Rakesh notices their relationship, he hatches a plot where he pretends to be Kamal, but his façade is blown very soon.
Kamal and Rakesh’s NCC professor could always tell them apart. After exams, Archana asks to meet Kamal’s family. Kamal takes her to Sarvodaya Orphanage and tells her about his life as an orphan. He explains to her his apprehension that Archana’s father would consider him an unsuitable match for her. Archana tells him that she will return to Dehradun and speak to her father regarding this problem.
On the other hand, Rakesh’s father and Archana’s father want their children to be married. When Archana tells her father about her wish to marry Kamal, her father initially disapproves, but he is convinced of Kamal’s suitability eventually. Incensed by these developments, Rakesh decides to kidnap Kamal from the orphanage and marry her in the guise of Kamal. In the confusion, it turns out that Rakesh’s friends kidnap Rakesh instead of Kamal, and Archana is married to Kamal as planned.
Some time after their marriage, Kamal enlists in the army and they bid farewell with heavy hearts. Their NCC professor, a senior in the force is taken aback when both Rakesh and Kamal come to enlist. On one of the training days, Rakesh creeps up to Kamal who was admiring a photo of Archana. Rakesh snatches it from him and makes a comment that offends Kamal and leads to a fight. The fight ends with one of them coming out of a pond, leaving a bloody pond behind with slight injury on him. He goes to Archana’s house and takes care of her injured husband. The presumed Kamal is seen disturbed and keeps reflecting back to the bloody pond. One day, the professor arrives at Archana’s house and delivers the sad news of Kamal’s demise.
Archana shows him that Kamal is home, and the Professor realizes that he is Rakesh. Archana breaks down upon receiving this news but plans to test this proposition out. Is it Kamal or Rakesh who has returned home as her husband? She tests her husband on three accounts that Kamal had performed earlier, and in all three instances, he fails. Archana files a case against him. In the court case, even Rakesh’s father has asked the court to punish his son, who has disappointed him with all his wrong doings.
Just as the Judge is about to sentence him, a new witness presents itself in court. The witness in question claims to be the actual Rakesh whose face has been injured. He gives an account of what had transpired. After the fight, Rakesh enlisted in Kamal’s place, and managed to barely survive under enemy fire. When he saw news of the case filed against the real Kamal, he started attending the trial in disguise. His conscience was stirred, and he finally came forward to save an innocent man from punishment.
Archana and Kamal reunite. Rakesh and his father embrace each other. Rakesh conveys his best regards to the couple. Honesty, truth and love prevails.