The goal of the present study was to investigate meanings of sexual intercourse in adolescence, and the relationships between meanings, gender, age, and sexual behaviors. Subjects were 201 Italian adolescents (107 boys and 94 girls), aged 14-19 (M=17.44, SD=1.65). Participants completed a battery of questionnaires on meanings of sex, sexual activity and other risk behaviors. Using confirmatory factor analyses and ANOVAs, we found:(1) four dimensions of meanings of sexual intercourse: negative social, personal, transgressional, and positive social meanings; (2) females scored much lower on all four dimensions; (3) negative social meanings were related to a lack of protection in sexual intercourse, whereas trangressional meanings were related to lack of protection at the first sexual intercourse only. Our findings suggest a similarity between meanings of sexual intercourse and meanings of others risk behaviors, including smoking. This similarity should be taken into account in prevention against health-risk behaviors in youth. (Contains 8 tables.)