Zameen Asmaan is the story of Kavita (Rakhee). Kavita is a widow whose husband Dr. Kailash (Shashi Kapoor) died in an accident years ago. Her son Sanjay (Sanjay Dutt) and Anita (Anita Raj) love each other. Even Kavita has no objection to their match. However, Anita's parents are against their relationship. Anita's father claims that Sanjay cannot be Kavita's real son , as he knows that Kavita is infertile. Then who is Sanjay's mother ? What is the secret?