Sanam Teri Kasam is an action romantic drama. The movie revolves around a man named Ramlal, who is falsely accused of a murder, which compels him to escape from the city and leave his wife and son, Sunil (Kamal Haasan) behind. However, while running away, he meets a dying man, who entrusts him with his daughter Nisha and his extensive property. He starts living a different life and raises Nisha like his own daughter, but his past comes knocking at his door, where he is informed that one of his employees is his long-lost son. However, much later, it is revealed that he is being cheated, and his son Sunil aka Sunny, is one who is in love with Nisha. Will Ramlal be able to realise the truth and finally unite with his real family after so long?