OFFICIAL USE ONLY ABSTRACT An intensive radiological survey of the islands of Bikini Atoll was conducted in April-May 1967 for the purpose of determining the levels and components of the external gamma radiation fields in this former weapons testing area. Fourteen islands and the two island complexes of the atoll were surveyed with instrumentation which included a field gamma spectrometer system, a high pressure ionization chamber, scintillation and G.M. survey meters, and thermoluminescent dosimeters. A large number of soil samples were taken for laboratory NaI(T1) and Ge(Li) gamma spectral analysis. Total exposure rates were found to vary considerably from site to site and island to island. Levels measured over soil ranged from less than 10 pr/hr to over 500 ur/hr. Major contributors to the radiation fields porte —w ky a usually included *87 a5, =" Co, *#2sn, and *o2Meh with a large number of other isotopes present. The large amount and consistency of the data indicate that a reliable and comprehensive picture has been obtained of the external gamma radiation environment of the atoll.