South Africa is in the grips of a devastating HIV/AIDS epidemic in which the peak incidence occurs among 15-24 year olds. loveLife is the largest youth focused intervention aimed at HIV prevention in South Africa. It is a national initiative of unprecedented scale combining a sustained multi-media awareness and education campaign with comprehensive youth-friendly sexual health services in public clinics nationwide, and countrywide outreach and support programmes. This joint initiative between government, non-government organisations (NGOs) and academic institutions aims to reduce HIV, other sexually transmitted infections and unwanted pregnancy among South African youth. It is difficult to attribute the impact of loveLife as distinct from the effects of other national HIV prevention campaigns. For this reason there are two main objectives of this National Evaluation. The first objective is to identify trends in HIV infection and related determinants of infection among young people. The second objective is to try and gauge the relative impact of loveLife on HIV and related risk behaviours. This National Youth Survey is the first of three such studies to be conducted at approximately two year intervals over the expected duration of the loveLife initiative, to track changes in HIV prevalence and sexual behaviour among South African youth. The aims of this initial study are to:· establish the prevalence of HIV and related behaviours among young people aged 15- 24 years; assess young people's sexual attitudes; examine the extent of young people's exposure to loveLife; undertake this data collection with sufficient accuracy to permit monitoring of trends over time.