INTRODUCTION. © On March 1, 1954, fallout occurred on some of the Marshall Islands as a result of a nuclear detonation at the Eniwetok Proving Ground. At that time 82 people were evacuated from Rongelap and Ailiginae Atolls and 154 from Utirik Island. to Utirik. In June of 1954, the 154 were returned Since March 1954 periodic surveys have been made of these Tslands to investigate the degree of contamination. Soils and biological collections were made on and around the Marshall Islands by the Applied Fisheries Laboratory (AFL) of the University of Washington on March 26, 1954, December 18, 1954, January 29, 1955, October 21-23, 1955, and July 1956; by the Naval Radiological De- fense Laboratory (NRDL) on February 1955 and February 1956. Analyses of the samples were performed by AFL, NRDL and by the Health and Safety Laboratory (HASL) of the Atomic Energy Commission. Surveys were also made of residual activity in the Pacific Ocean by Health and Safety Laboratory of the AEC and Office of Naval Research: in February-May 19553 by the Applied Fisheries Laboratory in June and September 1956. In addition, teams of medical experts from the United States examined and cared for the Marshallese following their exposure in March 1954, and returned to reexamine the Rongelapese at about six months, one year, and two years after exposure. The purpose of this report is to abstract the highlights of the findings from these investigations. tentionally In doing so there is the risk of unin- quoting the original reports out of context. It should be understood that the original authors are not responsible for any