During the second half of World War II, U.S. and Allied military and civilian scientists cooperated in helping the armed forces combat malaria. They worked through the Offices of the Surgeon General of the U.S. Army and the U.S. Navy, the National Research Council, the Board for the Coordination of Malarial Studies, the Office of Scientific Research and Development, the Australian Military Mission, and the British Medical Research Council, all in Washington, D.C. The Board for the Coordination of Malarial Studies, which the National Research Council established in November 1943 to guide research expansion and coordinate joint efforts, became the focal point for collaboration on research. These alliances produced hundreds of malaria studies and thousands of new compounds, some of which tested superior to traditional antimalarial drugs. This cooperative effort improved chemotherapy for the prevention and treatment of malaria after years of neglect in the development of antimalarial drugs. This article focuses on the establishment of the Board for the Coordination of Malarial Studies, the development of new antimalarial drugs, and collaboration with allies on drug research. The latter produced special U.S.-Australian and U.S.-Britain relationships.