Raju (Anil Kapoor) is the only son of his wealthy land owning father Prem Chaudhary (Akash Khuranna). Raju had lost his mother at birth and feels deeply deprived of a mother's love.
On Raju's 5th birthday party, as a promised birthday gift, Prem brings home a new mother Lakshmi Devi (Aruna Irani), hoping that she will be a doting and caring mother for Raju. However, Lakshmi Devi turns out to be greedy, shrewd and cunning. She married Raju's father only for his vast fortune, money and property. Together with her brother Totaram (Anupam Kher) and his wife Mynavati (Bharati Achrekar), they conspire on how to transfer all property to Lakshmi Devi's name. However, Lakshmi Devi and Totaram are enraged when they find out that Prem's first wife had prepared a will before her death transferring all property to Raju, and that Prem is only a trustee to all the wealth. In the will, it has been written that Raju will have full control of his property only after marriage and unless his wife jointly consents with him, he will not be able to transfer his wealth and property to another name.
Lakshmi Devi begins her vile schemes. On the front, she puts up an act of being a very loving mother for Raju, who exhilarated for a mother's love, becomes a devoted son. He showers Lakshmi Devi with love and respect, ever-ready to obey her every word. In the process, unknowingly, he allows Lakshmi Devi to manipulate him. She very cunningly misleads Raju to give up his education. When his father finds out that Raju stopped going to school at Lakshmi Devi's instructions, he called out to her to question her. Lakshmi Devi and Totaram, hearing Prem, pours oil on the steps causing him to fall down the flight of stairs and hurting his head severely. Using this opportunity, they prove that Prem has become mentally unstable and they lock him up in a corner room of the house.
Raju being naïve and uneducated, believes every word of his step-mother and her brother. Over the years, Lakshmi Devi increasingly isolates his aging father from the family and mainly Raju.
One day, Raju meets Saraswati (Madhuri Dixit) at a wedding and falls head over heels in love with her. After some pursuing and an intense incident in her village, Raju and Saraswati get married. In the meantime, Lakshmi Devi fixes an alliance for Raju with an equally uneducated girl from their own village, so that she too can be manipulated and can finally succeed in transferring the property in Lakshmi Devi and her son, Ramesh (Adi Irani), Raju's step brother's name.
Lakshmi Devi is shocked to learn about Raju and Saraswati's marriage as Lakshmi Devi knows that Saraswati was not only educated but also a very intelligent girl. As usual, Lakshmi Devi puts on an act of a doting mother in front of Saraswati. But Saraswati soon discovers that Lakshmi Devi, Totaram, Mainavati, Ramesh and his wife Kunika (Kunika) are all scammers and that their love for Raju is only a ruse. She challenges to expose their deceit to Raju.
First thing, Saraswati takes Prem to the temple thus releasing him from the confined room of 20 years. This bold step of Saraswati antagonises Lakshmi Devi. Lakshmi Devi clearly disapproves of her guts. But Saraswati successfully proves to all that his father was normal. Initially, Saraswati had to bear the brunt of Raju's anger when she tried to convince him of his mother's conniving intentions. After which, Saraswati cleverly exposed every one who had been cheating Raju over the years. For every attempt of Lakshmi Devi's schemes, Saraswati wittingly plays and backfires their plans ensuring that Raju gets the message without being offended.
In one incident, Saraswati, along with Prem and their faithful servants Pandu (Lakshmi Devikant Berde) and Champa (Priya Arun), planned for Lakshmi Devi to slip and fall, forcing her to be bedridden. Promptly, the responsibility of the entire household is handed over to Saraswati. Lakshmi Devi is infuriated and plots to get rid of Saraswati just for rewards.
When Saraswati becomes pregnant, her father, Shyamlal (Satyen Kappu) comes home with hoards of sweets for her in-laws and a box of saffron. He requests that a pinch of saffron be mixed with milk and be given to Saraswati. Lakshmi Devi, adds poison to the box of saffron. She prepares the milk and tells the unaware Raju to give Saraswati the milk along with a pinch of the poisoned saffron. Champa, who witnessed Lakshmi Devi mixing the poison, runs to Saraswati's rescue, narrating everything that happened and warns her against drinking the poisoned milk. A devastated Saraswati informs Raju the same. But blinded by Lakshmi Devi's love, Raju not only refuses to believe her, he even accuses her of conspiring stories against his mother. In defense, Raju drinks the poisoned milk to prove to Saraswati her error. Raju's world comes crumbling down when he coughed up blood.
He, then recollects and realises that everything he had heard about Lakshmi Devi all these years from others were eventually true. Yet, Raju cannot bring himself to hate Lakshmi Devi. His words to Lakshmi Devi before dying touched her deeply. Lakshmi Devi repented that her greed for wealth stretched a bit too far this time to the point of killing a son who had loved her with a true heart.
Saraswati, in the meantime, rushes to get a doctor. On returning she is told that if she wants Raju alive she will have to sign the property transfer papers. Saraswati agrees immediately. However, Lakshmi Devi forbids Saraswati from signing it and apologizes to her. A fight ensues between Lakshmi Devi and Ramesh. Totaram and Mynavati also joins with Ramesh. Ultimately, it required Raju himself to come forward to save Lakshmi Devi from being killed by Ramesh.
Eventually Raju recovers and hands over the signed property papers to Prem. He bids good-bye to his father, Pandu and Champa. He boards the vehicle with Saraswati to leave his home for good, when Lakshmi Devi begs him not to leave. To prove her remorse she rips up the papers and tells him that all she wants is nothing more than "her son". The family is happily reconciled.
