In an analysis of melanoma incidence for 1969 to 1978 among 11 308 workers at the Los Alamos National Laboratory in New Mexico 6 cases were detected in the total cohort, in which 5.69 cases would be expected (standardised incidence ratio [SIR] = 105; 90% confidence interval [CI] = 51,198) on the basis of incidence rates for the State of New Mexico, specific for age, sex, and ethnic origin. Among the White non-Hispanic men, 3 cases were detected, whereas 4.4 would be expected. The associated SIR of 68 (90% CI = 23, 163) does not suggest excess melanoma incidence in this subcohort. A direct comparison with Statewide incidence rates gave similar results. These results do not agree with the threefold excess of malignant melanoma incidence found among White male employees at the Lawrence Livermore National Laboratory.