Results of a medical survey of the people of Rongelap in the Marshall lslands, carried out in March 1961, 7 years after the accident, are presented. A total of 267 people was examined, most of them on Rongelap Island and some at Kwajalein and Majuro Atolls. Physical examinations showed no acute illnesses present nor any diseases which could be directly associated with radiation effects. However, lt was noted that several of the older people, particularly in the exposed group, were becoming quite feeble and helpless. Residual skin changes in areas previously showing lesions from fall-out were present with certainty in about 10 people. Dental examinations revealed no differences between the exposed and unexposed group. Examinations for the detection of such late effects of radiation as cancer and leukemia revealed no evidence of malignancies in any of the people, exposed or unexposed. Results of growth and development in children and hematological studies are also given. (P.C.H.)