The age relationship between sunburns and malignant melanoma was investigated in a population-based, matched, case-control study from the South Swedish Health Care Region (the highest risk area for melanoma in Sweden). Between 1988 and 1990, a total of 400 patients with a first diagnosis of malignant melanoma and 640 healthy controls aged 15-75 years answered a comprehensive questionnaire including questions regarding ultraviolet radiation exposure. In addition, a literature review was performed. The average number of episodes of sunburn per year was significantly associated with malignant melanoma (relative risk, RR = 1.9 for > or = three episodes per year versus never). Outdoor employment during the summer was associated with a decreased risk for the development of malignant melanoma (RR = 0.8). Data from case-control studies and migration studies concerning age relationship between sunburns and melanoma are inconsistent. From our own data, we did not find a higher risk of melanoma developed in individuals who had experienced severe sunburns in childhood. Instead, a significantly increased risk was associated with sunburns after age 19 years, RR = 2.2 for a history of more than five times versus never. Even if the hypothesis is biologically plausible, that episodes of sunburn early in life are associated with a higher risk of melanoma, so far epidemiological evidence is scarce. There is a need for better prospective epidemiological studies addressing this issue.