In 1996 a randomized sample of 4,020 Swedish adolescents from three birth cohorts were sent a questionnaire consisting of 50 items concerning habitual sun-related behaviours and attitudes, knowledge about melanoma, risk perception and self-image. A total of 2,615 questionnaires were returned. Girls sunbathed and used sunbeds more than boys at all ages. Sunbathing and sunbed use increased with age. Boys who were most satisfied and girls least satisfied with themselves sunbathed most. Those who were least satisfied with themselves used sunbeds most frequently. Girls reported a higher perceived susceptibility to melanoma than did boys. The perception of susceptibility increased with age. Those who were least satisfied with themselves reported feeling most susceptible. The overall main reason for sunbathing was appearance, both for own sunbathing, and to an even higher degree, as a supposed reason for other adolescents' behaviour, and was reported most frequently by girls and the older age groups. The second most 'important' reason for sunbathing was 'feeling warm and comfortable'. Preventive programmes aimed at a change of sun related behaviours among Swedish adolescents have to be tailored to the climate and cultural conditions and must take into account that having a tan, and the warmth of the sun, are highly valued by most adolescents.