STUDY OBJECTIVE: To describe the sexual behavior and contraception use among a sample of high school and vocational school adolescents in Barcelona, Spain. DESIGN: Cross-sectional study. METHODS: A random sample of 3139 students, aged 14 to 19 years, living in the city of Barcelona, were surveyed by means of an anonymous, self-administered questionnaire. SPSS/PC+ was used for statistical analysis. Significance criterion was set at 0.01. MAIN RESULTS: 13% of the students had previously participated in sexual intercourse; percentages between the sexes was equal. Frequency increased with age. Boys had their first experience at a significantly earlier age, but girls participated in sexual intercourse more often. The majority of adolescents used condoms as their primary contraceptive method; seven (3.3%) of the sexually active girls had been pregnant, and two (1%) boys had caused their partners to become pregnant. CONCLUSIONS: The rate of sexual activity among adolescents in Barcelona is low compared with those in both European and American studies. However, a higher rate of condom use is observed.