Daag is a story of a man convicted of murder, on the run from the law. Sunil is forced to leave behind his new bride Sonia when he kills her would-be rapist. In an attempt to establish a new identity Sunil meets Chandni and ends up marrying her to give her illegitimate child a father's name.

Now a respected Mayor of his town, Sunil's past catches up with him and brings together Sunil and Sonia but the long arm of the law is just a step behind.