Asha Parekh was offered the film but she declined. She did not want to play a vamp in her first film with Dilip Kumar. Bindu Desai, her previous co-star from Aya Sawan Jhoom Ke (1969) and Kati Patang (1970), later took the role. In her 2017 memoir, "The Hit Girl", Asha complimented Bindu's performance in this film.
Dastaan is a remake of B.R.Chopra's earlier film, Afsana which was released in 1951, both the films were written by I.S.Johar.
This is a scene by scene and dialog by dialog copy of another BR Chopra movie Afsana, released in 1951, where Ashok Kumar played the title role.
A well made movie, when it was released, it was ahead of its time.
Box office disaster.