The objective was to determine the impact of a multimedia device offering information about malignant melanoma on public knowledge, attitudes, and behaviors. Two municipalities in Sweden, Dalby and S Sandby, were chosen. The population of Dalby was exposed to the multimedia program during 1994-97, whereas the S Sandby population was not. A questionnaire was sent to random samples of the populations (10% of those aged 20-59 years) before (1994, n = 373 and n = 409, respectively) and after the intervention (1996, n = 375 and n = 418, respectively). Response rates were 74-89%. The groups were well balanced at baseline. In both areas women scored higher both at baseline and in 1996. Dalby women showed less fear of skin cancer in 1996 than in 1994 (2.13 vs 2.27, p < 0.01). This was not so in the controls. There was no major change in "sun behavior" in Dalby, whereas there was a negative change in S Sandby. After the intervention Dalby men had more "knowledge" (from 2.64 to 2.70, p < 0.05) and a tendency to better "sun behavior" (from 1.77 to 1.85, p = 0.076). There was no significant change over time in the S Sandby men. The multimedia program had a modest effect. The population in Dalby had more knowledge and changed its attitudes in a sun-protective direction. In the control area, the two-year follow-up sun behavior score was lower than at baseline. There was also significantly less fear of skin cancer after the intervention.