 During World War II, Gersh saw active service, joining an anti-tank unit of the 3rd Infantry Division in North Africa and Italy for four months, before being transferred to Special Services, where he met Beatrice Aberle, his future wife.In 1949, on his return to Hollywood, he bought Sam Jaffe's talent agency, which he renamed as the Phil Gersh Agency in the 1960s.His film-industry clients included Eddie Albert, June Allyson, Mary Astor, Richard Benjamin, Lloyd Bridges, Humphrey Bogart, Richard Burton, Lee J. Cobb, Harrison Ford, Gloria Grahame, Arthur Hiller, William Holden, Karl Malden, Fredric March, James Mason, Dorothy McGuire, Zero Mostel, David Niven, Don Siegel, Raoul Walsh and Robert Wise.