On Diwali, a young Vijay Khanna witnesses the murder of his parents committed by a man of unknown identity with a white horse on his charm bracelet Zanjeer.

When a traffic accident perpetrated by gang members leaves several children dead, a street performer named Mala becomes the witness where she is bribed by Teja's men to keep quiet.

Mala is questioned by Vijay, who becomes enraged at her and to sway her differently, takes her into the morgue to view the mangled bodies of the children.

When local criminals mocked him, De Silva vowed to get back at them by calling the inspector when a crime was about to happen.

Along with a concerted effort by Sher Khan to cheer up Vijay, Mala relents and vows that she will not try to control him and tells him to do what is right.

Sher Khan helps him to fight Teja and his men, where Vijay takes justice into their own hands until the police arrive.

The story and script were written by Salim Khan, who also conceived the "angry young man" persona of Vijay, played by Amitabh Bachchan.

[4] Zanjeer was written as a crime film with violent action sequences, and the main character Vijay was conceived as a hard-hitting, 'angry with the system' young man.

At the time, Bachchan was a "failed newcomer" who, by the age of 30, had twelve flops and only two hits (as a lead in Bombay to Goa and supporting role in Anand).

[4] For the female lead, Mumtaz was initially offered the role, but she was engaged at the time, and opted out, choosing marriage over career.

Jaya Bhaduri, who was engaged to Bachchan at the time, immediately agreed to take the role for the sake of her future husband.

However, the man was sometimes drunk, which led to him painting "Salim-Javed" on the wrong places, such as Pran's face or Bachchan's hands, for some posters.

[6] The music was composed by Kalyanji Anandji and the lyrics were written by Prakash Mehra, with the exception of 'Yaari Hai Imaan Mera', which was penned by Gulshan Bawra.