HIV/AIDS is one of the largest obstacles to development in many countries and is destroying the lives and livelihoods of millions of people around the world. Nearly 95 percent of all infected individuals are found in developing countries and the situation is especially problematic in sub-Saharan Africa. In Zambia, around 17 percent of the population is infected with HIV and AIDS is the most common cause of death. The study of HIV and AIDS has been dominated by two approaches; the biomedical and the ethical. This thesis turns to the field of economics in an attempt to widen the understanding of the spread of the epidemic. According to the empirical literature little attention has been given to the socio-economic context in which people live when it comes to understanding the disease. This thesis uses an economic model of risky sexual behaviour to investigate the correlation between different socio-economic attributes and HIV prevalence at district-level in Zambia. The empirical findings show that district HIV prevalence is positively correlated to expenditure, education and the proportion of female headed households, and negatively correlated to the proportion of women and fertility. Further research in this field is essential to establish what makes people susceptible to HIV infection. This research should preferably use individual data.