In 1928 he produced an adaptation of the Czech novel The Good Soldier Schweik. He was described by former Romanian Lt. General Ion Mihai Pacepa as being, "a devoted Communist who had a longstanding relationship with Moscow." He had founded the Proletarian Theater in Berlin in 1929.
According to Pacepa when Hitler came to power he sought political asylum in the Soviet Union. In 1937, he married dancer Maria Ley in Paris. Famous German theater practioner, and once Piscator's own dramaturge, Bertolt Brecht attended their wedding.
Piscator and Ley went to the United States in 1939. He became director of the Dramatic Workshop, which he founded at the New School for Social Research in New York City (1940). Among Piscator's students at the Dramatic Workshop were Marlon Brando, Tony Curtis, Judith Malina, Walter Matthau, Harry Belafonte and Tennessee Williams.
Until her death in 1999, Ley lived in New York while Piscator had to return to West Germany in 1951. Piscator was appointed manager and director of the Freie Volksbühne in West-Berlin in 1962. He produced the K.G.B. backed play The Deputy by Rolf Hochhuth which was part of the Soviet plan to defame and smear Pope Pius XII as a Nazi collaborator.