This paper outlines aspects of the HIV/AIDS epidemic scenario and the complexities associated with it. It reveals the socio-epidemiological patterns of the epidemic and in doing so identifies the populations with the greatest and fastest growing rates of infection. From the data presented it is evident that the pattern of HIV/AIDS in developing countries in sub-Saharan Africa in particular is unique. The pattern emerging in South Africa follows closely. The features of this pattern are as follows: the epidemic is mainly a heterosexual epidemic, the rates of infection in the general population are very high and the percentage of HIV-positive women is greater than men. An additional unique feature is the young age of onset of infection for women. These data demonstrate the need to focus our attention on young African women and the factors underpinning their predicament. In order to understand their position we examine the long standing relationship between social inequalities and health in general and further invoke the concepts of vulnerability and social capital to shed light on the position of women in the epidemic. Within the constraints of limited and problematic statistical data, the paper argues that a mixture and complex interaction of material, social, cultural and behavioural factors shape the nature, process and outcome of the epidemic in South Africa. It concludes with recommendations for the way forward.