The World Health Organization recently reported an 'alarming trend' of increasing Human Deficiency Virus (HIV) infection in the Islamic Republic of Iran. Adolescents form a particularly important target group for primary prevention. An anonymous questionnaire, derived from standard surveys such as the Safer Choices questionnaire and the 2001 Youth Risk Behavior Survey, was distributed to 1227 Iranian students attending 19 randomly selected high schools in Hashtgerd in 2002. Students reported that television (84%) and school teachers (66%) were the best sources of HIV/AIDS information, while parents (27%) and school books (15%) were least informative. Most students knew that heterosexual intercourse (90%) and shared intravenous needles (94%) can cause HIV infection; however, salient misconceptions were revealed. Only 53% were aware that condoms protect against infection through sexual intercourse. More effective school-based HIV/AIDS education is needed in Iran.