The ANZUS Treaty between Australia, New Zealand and the United States of America was signed on 1 September 1951. This volume of key Australian official documents, extracted from the files of the Department of External Affairs, about the negotiations that led to the ratification of the ANZUS Treaty has been published to commemorate the fifieth anniversary of the Treaty. This is a limited but representative selection of documents covering the period 1949-1952. The full range of Australian official documents is available to the public particularly through the National Archives of Australia in Canberra.