In a population-based, matched, case-control study from southern Sweden of 571 patients with a first diagnosis of cutaneous malignant melanoma and 913 healthy controls aged 16-80 years, the association between sunbed use and malignant melanoma was evaluated. A total of 250 (44%) cases and 372 (41%) controls reported ever having used sunbeds. A significantly elevated odds ratio for developing malignant melanoma after regular exposure to sunbeds was found, adjusted for hair colour, raised naevi, skin type and number of sunburns (odds ratio (OR) 1.8, 95% confidence interval (CI) 1.2-2.7). A dose-response relationship between total number of sunbed uses and melanoma risk was only found up to the level of 250 times. The OR was higher in individuals younger than age 36 years (adjusted OR 8.1, 95% CI 1.3-49.5 for regular vs. never use). The association seemed to be true only for subjects with black/dark brown or light brown hair and among females. Lesions of the extremities showed the strongest association of increased risk with sunbed use. An increased risk was related to commercial exposure and to exposure during the winter. The results substantiate the hypothesis that exposure to sunbeds might increase the risk of developing malignant melanoma.