The aim of this study was to investigate the quality and sources of teenagers' information about sex. Between October 26th and December 16th 1997, 277 pupils from lower and upper schools agreed to participate in this study. Two hundred and seventy (97.5%) of the pupils in this population declared that they had received information about sex. This information was provided principally by the media, followed by friends, boyfriends and girlfriends, the school and their parents. The information received concerned sexually transmitted diseases (STDs and AIDS), the consequences of sexual relationships, sexual hygiene and the signs of puberty. We found that 95.5% of the pupils knew about AIDS and gonorrhea and that 91.7% knew how to protect themselves against AIDS and STDs. Thus, most pupils had received information, from various sources, on sexuality. Parents played little role in the sexual education of their children, and the State was involved in various ways.