
Background: AIDS epidemic is currentlyin the third step of its emergence and has turned into an epidemic threatening the physical community. According to a report of WHO 68 million were infected with AIDS by December 2002 and adolescents were identified as the population at the highest risk of AIDS. Since the transmission routes of this disease are limited, an increase in the level of knowledge of people, especially the adolescents, about AIDS/HIV can be very helpful in the reduction of HIV infection. This study was conducted to investigate knowledge of and attitudes toward HIV/AIDS in male high school students in Semirom, Iran Methods: The population of this descriptive, cross-sectional study was male high school students in Semirom, Iran. The questionnaire included knowledge questions on the disease and its transmission routs and attitude questions on AIDS and its victims. The responses were based on a four-point Likert scale (“strongly agree” to “strongly disagree”). The data were analyzed by SPSS software through demographic variables. Results: Although around 80% of the students had accurate knowledge about the contagious nature of the disease, there were still misconceptions about the disease and importance of preventing HIV transmission in a way that around 35% of the students did not know the importance of observing hygiene in the prevention of this disease. Conclusion: We recommend that schools be considered as one of the central focuses in AIDS reduction strategies, and students’ training on all aspects of HIV/AIDS as a complementary part of school curriculum be seriously addressed by government and educational policy makers.