The analyses show that family structure was related to the use of contraception. Living with only one parent puts adolescents at a much greater risk of engaging in unprotected sexual intercourse. The results also suggest that family structure was important regarding sexual behaviors per se, and was not related to the relationship that adolescents had with their parents. Socioeconomic variables were significantly associated with having had sexual intercourse and engaging in unprotected sexual intercourse. The analyses show that adolescents who had access to more money and those who perceived their family as wealthier were more likely to have had sexual intercourse. For boys, the weekly disposable income was more strongly associated with engaging in sexual intercourse than the perceived family wealth. The implications of this study are important for parents, teachers, health promotion specialists, and others responsible for reproductive health of adolescents. Many studies have reported that gender, socioeconomic status, and family structure are significantly associated with risky sexual behaviors in adolescents; however, some inconsistent findings have emerged. Recent studies in Serbia have shown an alarming prevalence of sexually transmitted diseases (STDs) among adolescents. This cross-sectional study sought to investigate the relationship between family structure and socioeconomic status. The study included Belgrade schoolchildren 15 years of age who were enrolled in the first year of secondary school. Tables, references