Choper served as law clerk to Chief Justice Earl Warren of the U.S. Supreme Court following graduation from law school. He taught at the Wharton School of the University of Pennsylvania from 1957 to 1960, and at the University of Minnesota Law School from 1961 to 1965. He joined the Boalt faculty in 1965. Choper has been a visiting professor at Harvard Law School, Fordham Law School, University of Milan, Free University in Amsterdam, Autonoma University in Barcelona, University of New South Wales in Sydney, University of Lucerne in Switzerland, and Catholic University of Portugal in Lisbon and Porto. He served as Boalt Hall’s dean from 1982 to 1992. From 1979 to 1998, Choper was one of the three major lecturers at U.S. Law Week’s Annual Constitutional Law Conference in Washington, D.C. He has served on the executive committee of the Association of American Law Schools, and on the executive council of the American Academy of Arts and Sciences (of which he was vice president for more than ten years). In 1998 he received the UC Berkeley Distinguished Teaching Award and the Rutter Award for Teaching Distinction at Boalt Hall in 2006. In 2005 the Boalt Hall Alumni Association presented Choper with the Faculty Lifetime Achievement Award and the University of Pennsylvania Law School gave him the James Wilson Award, its highest award for alumni.