Kallu (Amitabh Bachchan) lives with his older brother, sister-in-law (Asha Parekh), and their little daughter. He spends his time idly playing with the neighbor's kids. His older brother gets into accident at work at the mill and loses his arms. He loses his job and needs money for treatment. Kaalia begs his brother's boss (Amjad Khan), but he refuses. Kaalia breaks into the boss' safe to get the money but it's too late as the brother dies. The boss throws Kaalia in jail for 9 months. This is where he meets the men that teach him crime (kallu se kalia ka safar shuro hota hai). After his release, Kaalia is a different, stronger man. He and his accomplices steal the gold that the boss had been smuggling at the mill. Then he burns down the mill as retribution for his brother's death. He goes to jail again, this time for 2 years. His accomplices lie to his sister-in-law by telling her that he is in America earning a lot of money for her and her daughter. They move from poverty into riches. In jail, Kaalia meets the warden (Pran), a smart, ethical, strong man, whose daughter was kidnapped by one of the prisoners when she was little. After Kaalia is released from prison, he is bent on seeking vengeance and eventually pairs up with a woman (Parveen Babi). The boss kidnaps Kaalia's niece and forces her mother to testify against Kaalia in a murder trial. He is found guilty for a murder he didn't commit and escapes from prison to find his niece. At first, the warden chases him and once he knows the true story, decides to help him. They go to the boss's place and not only find the little girl but also the sister-in-law about to die. The boss reveals to the warden that he was the one who had kidnapped his daughter 20 years ago, and now it's the grownup Parveen Babi's character. They fight with him, and the boss loses. Everyone lives happily after.