Given the exponential rate of growth of HIV/AIDS in the Western Cape in recent years, and university concerns about the health of students and others, knowledge about young peoples' ideas and social constructs of the virus and syndrome is important. Medical anthropology lecturers Fiona Ross and Susan Levine present here their preliminary findings about University of Cape Town student perceptions regarding HIV/AIDS. This paper shows that young adults tend to imagine that they have an immunity to HIV infection and so continue to practice unsafe sex, irrespective of their educational background and specific knowledge about HIV/AIDS. The data suggest a critical need to reassess the efficacy of education as a means of disease prevention, and to examine more closely the knowledge, attitudes and practices of young adults.