This study investigated sun protective behavior during snow sports and its psychosocial determinants. A longitudinal study was conducted among 418 Dutch adults who planned to go on a ski holiday. Participants were asked to fill in a questionnaire before and after their ski trip. In the baseline questionnaire several psychosocial factors were measured (i.e. knowledge, risk perception, worry, attitude, social influence, self-efficacy and intention). At follow-up, sunscreen use and frequency of sunburns were measured. The results showed that, despite their generally high intention, a substantial part of the respondents (40%) did not use sunscreen adequately during their ski holiday. Furthermore, one-fourth of the respondents reported at least one sunburn during their ski holiday. Men and younger respondents used sunscreen less frequently and were sunburnt more often. Sunscreen use was predicted by a positive attitude, high self-efficacy levels, high intention, high knowledge and high perceived risk. The background and psychosocial variables explained 32% of the total variance of sunscreen use. Suggestions for future research and interventions are discussed.