This paper investigates ethnic theatre in general, and Chicano theatre in particular, with a particular reference to Luis Valdez's famous play Zoot Suit. This paper is divided into two main parts. The first part tends to be an introductory theoretical one. It begins by surveying the history and development of the ethnic and Chicano theatres in the United States examining their impact on society. This part, also, highlights the remarkable role of Luis Valdez as the father of the Chicano theatre. The second part of the paper provides a comprehensive analysis of Valdez's Zoot Suit in order to find out how Chicanos are stereotyped in the play