Studies investigating physical activity among adolescents living in post-communistic Central-European countries are sparse, particularly in light of the fact that some research has identified that adults in these countries exercise less frequently than western counterparts. The purpose of this study was to investigate whether physical activity participation is associated with certain friendship factors, the ability to make friends, level of involvement with friends, and perceived friends' involvement in physical activity, among 1,886 Central-Eastern European high schools students. The results of this study corroborated previous research in other adolescent populations in which it has been found that overall participation in physical activity was lowest among adolescents who said that making friends was difficult, who were less involved with friends, and who reported that making friends was difficult. The association of these friendship factors and physical activity participation has important implications for health education. Friendship factors should be given serious consideration in health education strategies and research efforts designed to increase youth physical activity.