The film was never released in India. This caused many Indian fan's around the world to believe that the film was never completed and released. Even in Dev Anand's autobiography book , the film is listed as "Unreleased". The film may have had financial problems in releasing the film in India.

Zeenat Aman's voice is dubbed in the film.

Major portions of the movie were shot in and around Udaipur, where the James Bond movie Octopussy (1983) was later filmed. Anand's onscreen partner Rod Perry made his acting debut in The Evil Within, and he went on to become a Blaxpoitation legend, appearing in such movies as The Black Godfather (1974) and The Black Gestapo (1975) and the popular American television series S.W.A.T.

Zeenat Aman had already been cast in her debut role in Anand's Hare Rama Hare Krishna, which was released in 1971. The Evil Within became a trial run for Aman to get acquainted with the camera.