He made his film debut in Mandi directed by Shyam Benegal in 1983. From 1994 to 2008, Patel worked with the Indian theatre director Satyadev Dubey. In 1995, he joined the Indian National Theatre and appeared in the play Neela Kamra. His repertoire has included classical and modern Indian plays as well as plays by Western writers, e.g., Pinter's The Caretaker, Sartre's No Exit, Camus' Cross Purpose, Ionesco's The Lesson, and Mrozek's Vatzlav.
In the spring of 2007, Patel took the lead role of Eeshwar Dutt in Rafta, Rafta..., a comedy written by Ayub Khan-Din and directed by Nicholas Hytner at the National Theatre in London to critical acclaim and sellout audiences.
His credits include The Buddha of Suburbia, China Gate, Mr India and Run Fatboy Run. In 2009 he appeared in Coronation Street playing the role of Umed, Dev Alahan's uncle. Patel also appeared in Mr Stink, Gangsta Granny, The Boy in the Dress and Billionaire Boy, the television film adaptations of children's books by David Walliams. He plays shopkeeper Raj in all the films, although they are set in different places.