Khiladi 420 is an action comedy story with Akshay Kumar playing a double role. Akshay looses heavily of cricket betting and does not have money to pay to Mukesh Rishi, the betting don. Mahima Choudhary is the only daughter of a big industrialist, Alok Nath. Akshay posses as a rich NRI from Canada and wins Alok's confidence and Mahima's love. But before the marriage, Alok comes to know about Akshay and Akshay kills Alok. The police warns Mahima about Akshay, but she refuses to listen and they get married. On the wedding night, Mahima comes to know that Antra Mali is the mistress of Akshay and that he had married her for money. There is a fight between them and Akshay is killed. Akshay's twin brother comes on the scene and posses as Akshay to save Mahima from murder charges.