Introduction. In Serbia, there have been no broad campaigns or educational programs focused on adolescents’ sun protection. Objective. The aim of the study was to assess whether an educational program would have impact on changes of attitudes and sun-protective behaviors of high school students. More specific aim was to examine whether sex and age differences in sun behavior exists. Methods. Educational program was designed to provoke changes in attitudes towards sun protection and sun behavior. The investigation was carried out in Belgrade, Serbia in two educational cycles, during spring 2007 and 2008. Sixteen- and 17-year old high schools students were targeted and assessed before and after the educational intervention by means of self-report questionnaire designed for this study (about skin types and sun behavior). The students’ attitudes towards sun protection and sun behavior before and after the educational intervention were compared and analyzed by the Pearson's chi-square test and logistic regression analyses. In the second educational cycle (2008) age and gender differences in sun behavior were analyzed. Results. Overall 3205 students in 2007, and 2155 students in 2008 year from 11 high schools participated. A statistically significant behavior change was observed for the use of sunglasses in 2007 - the number of students using them increased from 41.6 % to 45.6% (p<0.05). There were no significant changes in other ways of protection i.e. sunscreen use, protective clothes or staying in shade. Conclusion. Educational program had an impact, but broader activities involving schools, local communities and media are needed for significant changes in sun behavior and attitude.