Patekar was born Vishwanath Patekar on 1 January 1951 in Murud-Janjira in Raigad District, Maharashtra, to Gajanand Patekar, a small textile printing businessman, and Nirmala Patekar, a housewife. He is an alumnus of the Sir J.J. Institute of Applied Art,Mumbai.
Patekar has played many types of roles. He has played the occasional villain but been a hero in most of his films. He acted in movies such as Gaman (1978), Mohre (1987) and Salaam Bombay! (1988) and was noticed by the mainstream Bollywood industry for his portrayal of the villain in the 1989 film, Parinda, for which he won his first National Film Award for Best Supporting Actor. He was also awarded the Filmfare Best Supporting Actor Award for the role.
He turned director with his movie Prahaar: The Final Attack co-starring Madhuri Dixit. He underwent training for his role as an Indian Army officer in Prahaar and was awarded honorary Captain's rank. He joined the Territorial Army in the early 1990s.