Whilst shooting in Kolkata for a song in a stadium. Neetu Singh started crying, who had recently got engaged and didn't want to be away from Rishi Kapoor. The phones in Kolkata weren't working and Rishi was upset that he couldn't get through to Neetu. Amitabh Bachchan asked Neetu why she was crying. Neetu said, she wanted to go back.' Amitabh called the producer, asked him to book Neetu's ticket back to Mumbai and said they would manage the song without Neetu. The whole song was changed. This is the reason why Neetu is in half of the song and then disappears.
When director rakesh kumar wanted to make this film, amitabh was busy with other films, then rakesh kumar, one day saw Amitabh"s diary and saw that Amitabh is free before 8 am morning, so the maker convined amitabh to shoot for him daily from 7am morning to 8am till the film was complete. So this film was shot daily for about one hour. In the lp record of yarana only male singers mohdrafi & kishore kumar have sung all songs of the film.
Due to Neetu Singhs unavailability to dub a few scenes, Rekha was called upon to finish her dubbing work.
The scene where Amitabh Bachchan attempts to learn how to dance {But purposely starts a fight with everyone else dancing},has a instrumental song. The song is Santa Esmeralda's - "The House Of The Rising Sun" - The 14 minute version. They used the opening hook of the song and the middle instrumental part. The song was later sampled by Missin Linx for the song "What It Is".
During the the song 'Saara Zamaana', the light bulb outfit went on and off via a switch which was firmly placed in Amitabh Bachchan's hand. He had to press the switch on-off in tune with the beat of the song. The mastermind behind this idea of the outfit was Amitabh Bachchan himself.