The incidence of malignant melanoma and non-melanoma skin cancers has increased rapidly in Sweden as well as in other western countries during the last 20 years. Adolescents are an important group in skin cancer prevention. Interventions targeting this group have been reported to affect knowledge and attitudes, but the effect on sun protection behaviour has been slight. The aim of this study was to investigate the applicability of the Transtheoretical Model (TTM) for skin cancer prevention for adolescents. A random sample of 1200 18-year-olds living in Stockholm County was selected from the national census registry. A questionnaire that included three of the major constructs of the TTM (i.e. stages of change, processes of change and decisional balance) was sent by mail. The majority of the teenagers were in the precontemplation stage for giving up intentional tanning. The relations between the stages of change and two other major constructs of the TTM, processes of change and decisional balance, were consistent with data on other health behaviours. The results may aid in developing successful skin cancer prevention programmes. The results give support for the stages of change measurement used in this study and that utilizing the TTM in skin cancer prevention may be appropriate.