Dil Ne Jise Apna Kahaa begins with Rishabh (Salman Khan) and Pari (Preity Zinta) who are deeply in love. He is a wealthy young man, working in an advertising agency while she is a hardworking, dedicated doctor. They marry and soon Pari is pregnant. Pari has a dream to create a hospital for children. Tragically, she is involved in an accident and dies in hospital. Pari's last wish was to donate her heart to her patient Dhani (Bhoomika Chawla). Rishabh is devastated and opposes the plan to donate the heart; he goes ahead with Pari's last request: the creation of a children's hospital.
Dhani is cured, much to the joy of her family and her grandmother (Helen). Rishabh has gone into depression but soon comes across Pari's project to build a hospital for children. He begins to develop the hospital. Soon enough Rishabh and Dhani come across each other, and she feels an instant attraction to him. Rishabh ignores her advances as he is still very much in love with Pari. Rishabh does not know that Pari's heart was given to Dhani but soon he realizes that. When he does, Dhani faints. While she is in the hospital, with doctors struggling to restart her broken heart, he falls in love with her. He tells her that he loves her, and if she loves him, she will pull through. She does, and the two get together.