Surveys were conducted to estimate the extent to which knowledge, misconceptions and attitudes of adolescents in Tunisia towards HIV/AIDS had changed after a period of five years. A population of school-going adolescents of both sexes, age 16 to 20, was sampled in 1997 and again in 2002. We found that HIV/AIDS and sexually transmitted diseases became better known, there was more tolerance expressed for people living with AIDS, and the use of condoms was more positively judged. Fewer misconceptions surrounding the condition were also noted. However, many results recorded during the 1997 survey remained unchanged (e.g., scepticism about awareness campaigns; TV as a primary source of information). We discuss the socio-economic and medical/social context in Tunisia during the period 1997–2002 that seemed to allow adolescents to improve their knowledge of HIV/AIDS and to acquire positive attitudes towards persons living with the condition.