STUDY OBJECTIVE: To evaluate the effects of a German public education campaign which aimed to improve knowledge on risk factors for malignant melanoma. DESIGN: Comparison of data from two successive cross sectional surveys conducted before (spring 1993) and after (autumn 1994) the campaign. SETTING: All 56 nursery schools in Göttingen, the capital of southern Lower Saxony, Germany. PARTICIPANTS: Parents of children attending the nursery schools. Altogether 1341 questionnaires from parents were included in the first survey (response rate 64.9%) and 1150 questionnaires in the second survey (response rate 61.4%). MAIN RESULTS: The respondents in the second survey were much better at distinguishing true melanoma risk factors from false ones. The distribution of scores measuring the degree of accurate knowledge about melanoma risks indicated that this had improved significantly (p