Mithun Chakraborty was the first choice for Kawaljeet's role.
Composer Rahul Dev Burman asked singer Annette Pinto to gargle a tune to create a score for the Evil look-alike Babu character played by Amitabh Bachchan. The inspiration behind the gargle like effect may have been taken from 0:25 of the song "My Name is Nobody" -The Wilde Horde by Ennio Morricone. There the flute is like the gargling effect in Babu's entry.
Rekha was first signed for the role eventually played by Hema Malini. Then Amitabh decided to stop acting with Rekha and Parveen Babi replaced her. When Parveen Babi suffered her nervous breakdown, Amitabh requested a pregnant Hema who had cut her assignments, to step in.
Babu' s theme music was reused in the film Andar Bahar, and Vinod Khanna's Insaaf and Thikana.
The Longest Day by Paul Anka was sampled for the song " Zindagi Milke Bitayenge".