This dissertation examines the meanings and uses of medicine for American Jews from 1945-1955. Focusing on medical activism in the United States, Europe, and Israel, I argue that medicine provides a lens with which to interpret the enormous changes of the immediate postwar decade among American Jews. In an era concerned with the need to heal and rebuild in the wake of the Holocaust, there was an urgent need for American Jews to become “caretakers” for world Jewry and medicine served as part of that effort in both Europe and Palestine/Israel. In the wake of the war, American Jews spearheaded efforts to rebuild medical networks, provide medical aid to Jewish displaced persons in Europe, and build medical infrastructures in Palestine and Israel. Through a new assertiveness and confidence of American Jewish medicine and health care activism, prewar Eurocentric world views of Jewish medicine shifted to a postwar US/Israel axis. Yet, the relationship between many American Jews and Israel remained uneasy and there were still lingering concerns about dual loyalty.