Tambor first moved to repertory theater in Milwaukee, later making his Broadway debut in the comedy Sly Fox (1976), appearing with George C. Scott and directed by Arthur Penn. He appeared in Measure for Measure in the same year. In 1979 he starred in Norman Jewison's . . . And Justice For All, as a lawyer friend of the protagonist, Arthur Kirkland (Al Pacino). In an early TV job, an ad for Avis rent-a-car, he was seen running (huffing and puffing) through an airport, mocking O. J. Simpson's "Go, O. J. , go!" ads for Hertz. He has had a significant career in episodic TV, where he made numerous guest appearances on different shows, including Taxi, Kojak, M*A*S*H, The Golden Girls, and Three's Company. In 1979 Tambor got his first role as a main character in television in the short-lived show The Ropers. Throughout the 1980s Tambor had a recurring role on Hill Street Blues playing a defense attorney who eventually becomes a judge. In 1981 he appeared in an episode of Barney Miller as a man who was trying to bring exposure to the members of the Trilateral Commission in charge of the coming New World Order. In 1987 and 1988, Tambor appeared as a regular on the prime time ABC series Max Headroom as Murray, Edison's editor. In 1990, he appeared in the music video for the Phil Collins song "I Wish It Would Rain Down".