Sanjeev Kumar played 9 roles.
Naya din nayi raat was offered to Dilip Kumar fist but he suggested the makers of the movie to take Sanjeev Kumar.
Sanjeev Kumar was attacked by a lion during the shooting of the film.
One evening Chandra Barot accompanied Amitabh Bachchan and Jaya Bachchan for her newly released film Naya Din Nayi Raat at then popular cinema hall Ambar Minor Oscar (now Shoppers Stop) in Andheri.This was during the early stages of Don 1978.Sanjeev Kunar had 9 roles in Naya Din Nayi Raat but what caught Chandra Barot's eye was the seventh character he played of troupe owner.Sanjeev Kumar's wardrobe inspired him to make a similar character for Amitabh Bachchan in Don who later turns police informer.