A high incidence of malignant melanoma has been reported among several professional occupations.7 22 It has been postulated that the high incidence may result from intermittent and intense sun bathing habits linked with high social class, high education, affluence, and the accessibility for sun holidays among groups usually working indoors.7 23 24 A recent study was without persuasive evidence of occupational risk factors.24 The SIR of 10–25 for malignant melanoma in the present study is remarkably high. In a recent review of the causes of malignant melanoma there was no study that showed such a high risk, however, there were also studies in which no relation between sun exposure and malignant melanoma was found.25 High incidence of malignant melanoma has been related to radiation in some occupational studies,26–29 but not in the Los Alamos study,30 or in a mortality study of British radiation workers.31 The follow up time may have been too short in that study to detect skin cancer in general, and particularly as skin cancer and skin melanoma have good survival.32 Thompson et al reported that in an incidence study in Japanese survivors of the atomic bomb, non-melanoma skin cancer was associated with radiation exposure when followed up to 1987.32 However, malignant melanoma of the skin, which is at a much lower incidence among Japanese than among northern European people at similar latitudes is not mentioned.33 For that reason it may be difficult to evaluate the risk of malignant melanoma among survivors of the atomic bomb.