Tinnu Anand was chasing Amitabh Bachchan for a year to narrate his script, from studio to studio, and every time Amitabh would say not today, tomorrow, due to the fact he had a really busy schedule.
Finally, Tinnu had cornered Amitabh on the sets of Don and finally narrated his script. When Tinnu finished, Amitabh was silent. Tinnu said, "You don't have to tell me that you like my script because I know you like it very much." Amitabh was surprised and asked, "How do you know that? "Tinnu replied, "Before I came, a few people told me that if Amitabh Bachchan is hearing a script and he looks towards the sky and he starts stroking his hair, it means your script is rejected. I am glad you did neither while I was narrating the script.' Amitabh Bachchan liked Tinnu's confidence and signed the project.
The now-iconic dialogue from the movie, "Hum jahaan khade ho jaate hai, line wahin se shuru hoti hai" (Where is stand is where the line starts from) is considered to be one of Amitabh Bachchan's most popular dialogues. However, the line is actually spoken first by Bob Christo. Amitabh only repeats it.
The song "Jahan Teri Ye Nazar Hai" was filmed on the sets of Namak Halal (1982), another Amitabh Bachchan Blockbuster. This was due to financial and time constraints
Whilst filming Amitabh Bachchan wanted to change a particular dialogue, which was: 'Tu aatish-e-dozakh se darata hai jinhe hain woh aag ko pee jaate hain paani kar ke'. Director Tinnu Anand was adamant for not changing it as it was written by his father, Amitabh thought the dialogue was very inconsequential and did not want to say it. This debate got to a point where Amitabh told the director to change the actor if he didn't change the dialogue. The director was firm on his decision when Amitabh saw he was very adamant, he gave up and told the director that since he was very stubborn, Amitabh would say the dialogue. But he added if the dialogue got an applause from the audience, he would give up acting. The dialogue in fact did get an applause and Amitabh did not give up acting either.
The background music done by RD Burman was very creative. For example, during the exact scene when Amitabh walks from his house to the house of Ram Din's (The man awaiting for his wife to have a baby), a funny background music sound is used. This was sampled and remade from Gary Wright's song "Love is Alive" at the 0:20 mark. It was the guitar bass part of that song.