摘要：Recently HIV is falling in a significant number of countries, partly due to the adoption of preventive behaviors, which demonstrates that decreasing sexual transmission of HIV is possible. The aim of this research was to analyze preventive sexual behavior in Portuguese adolescents, including information and attitudes about HIV/AIDS, and assessing whether they changed from 2002 to 2010. Data were collected through a self-administered questionnaire from the Portuguese sample of the Health Behaviour in School-aged Children (HBSC), a collaborative WHO study. The study provided national representative data of 10587 Portuguese adolescents, randomly chosen from those attending 8th and 10th grades and the opportunity to examine trends in sexual behaviour on a national level. In terms of preventive behaviours, results showed an increasing trend regarding the percentage reporting first sexual intercourse at 14 years old or more and condom use at last sexual intercourse and a stabilized trend concerning having had sexual intercourse and contraceptive pill use. Nevertheless, in terms of information and attitudes about HIV/AIDS, results showed a systematic decreasing trend.
