One of the most consistent findings in social epidemiology is an inverse relationship between indicators of SES and most types of illness. However, a growing body of research on HIV in sub-Saharan Africa suggests an intriguing reversal of this pattern, particularly with respect to HIV among women. In Cameroon, specifically, high-SES women have higher rates of HIV infection compared with low-SES women. Using data from the 2004 Cameroon DHS, this study explored the relationships between SES and HIV and tested a multivariate model designed to highlight the distinctive factors associated with increased risk of HIV among women in different SES classes. The results revealed that high-SES women who reported engaging in riskier sexual behaviour had the highest levels of HIV infection. Surprisingly, among this group increased knowledge of HIV, more domestic decision-making authority and access to health care did not reduce vulnerability. Meanwhile, among low-SES women relative gender inequality was significantly related to HIV risk. Specifically, among this group of women, having a partner with higher education was strongly associated with greater HIV risk. The results suggest that different approaches targeting each sub-group are needed to effectively combat the disease.