A case-control study of occupational and recreational sun exposure, Mediterranean and other sun-exposed holidays, tanning history and history of isolated episodes of severe sunburn has been carried out on 113 patients with cutaneous malignant melanoma and 113 age- and sex-matched controls. Social class and skin type were also considered in the analysis of the data which involved the use of conditional multiple logistic regression. A highly significant increase in the history of severe sunburn was recorded in melanoma patients of both sexes in the 5-year period preceding presentation with their tumour. Higher social class and negative history of recreational sun exposure were also significantly increased in patients by comparison with controls. In the male group severe sunburn, lack of occupational sun exposure and higher social class were significant factors while in the female group only severe sunburn was significantly increased in the melanoma patients. This study thus provides evidence to suggest that short intense episodes of UV exposure resulting in burning may be one of the aetiological factors involved in subsequent development of melanoma.