This action-oriented crime drama revolves around the twists and turns in the life of Kaalia (Amitabh Bachchan), a simple young man who lives with his older brother (Kadar Khan), sister-in-law (Asha Parekh), and their little daughter. He spends his time idly playing with the neighbour'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 nine months.
In the violent and dangerous environment of prison, he meets the men who 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, 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 grown up Rani Singh (Parveen Babi. The criminals are defeated in battle, all ends well for Kaalia And Rani.