Hoshiyar is an action-comedy drama. The movie revolves around Sitadevi and her family; she lives a comfortable life with her husband and two sons - Rakesh (Jeetendra) and Rajesh (Shatrughan Sinha). However, things take a turn when Sitadevi’s husband dies, and his friends take over all his wealth by betraying Sitadevi and throwing her and her sons out of the property. Sitadevi decides to leave the city along with her sons; however, Sitadevi and Rakesh are separated from Rajesh by accident. Rakesh grows up as a singer, while Rajesh takes the life of crime and becomes hitman. Circumstances turn in such a way that Rajesh is assigned the task to kill Rakesh. Will Rajesh unknowingly kill his own brother?