OBJECTIVE: To describe the role of sexual experience based on information and sociocultural contexts for the risk of HIV/AIDS transmission in adolescents. METHODS: A questionnaire was answered by 1,386 middle school students from the state of Santa Catarina, Southern Brazil, in 2000. The instrument included the following variables: personal characteristics, sexual experience, communication context and knowledge on AIDS, attitudes towards condom use, risk and protective behaviors and feelings. Data analysis comprised statistical description and relational analysis (Chi-square and mean comparison tests). RESULTS: Lack of knowledge about HIV transmission was related to peers as main information source (p < 0.05). Steady romantic relationships are the predominant context for sexual relationships with penetration (p < 0.001). AIDS protection was associated to three factors: ongoing relationship, number of sexual partners and safe sex (P < 0.001). A positive attitude for condom use is favored by talks about sexuality and the intention of condom use (p < 0.001). The obstacles to condom use are: having had recent sexual relationships, risk behaviors, inadequate knowledge and dependence of television as an information source (p < 0.005). CONCLUSIONS: The practice of safe sex is affected by adolescent's level of information, their attitudes about condom use and fear of the epidemic. Reevaluating prevention through multipliers strategy as well as reappraisal of family as mediators and the use of appropriate materials about Aids for teenagers are recommended.
