Humshakal is an action comedy drama. The movie follows the story of a young honest Police Officer, Inspector Vinod (Vinod Khanna), who lives with his mother, wife and daughter, and is unaware of the fact that a dreaded criminal Dadu Kaliya is his lookalike. Later, Inspector Vinod gets killed by a criminal Devi Dutt (Kader Khan), however, Vinod’s colleague, Commissioner Din Dayal Kapoor (Shammi Kapoor) hides the news from Vinod’s family. He instead asks Dadu Kaliya to pose as Inspector Vinod in front of the world. The question remains, how long will the Commissioner be able to hide the truth from everyone?