AIDS is a human tragedy and a major health problem. The scale of the disease is so large that it now raises questions about the impact of AIDS on the future development path of many of the world’s poorest developing countries. Through its effects on population levels and growth rates and on macroeconomic growth, AIDS may influence the prospects for achieving food security in the developing world by the year 2020. AIDS is most prevalent in Sub-Saharan Africa. AIDS imposes both direct and indirect costs on its, as on all, national economies. AIDS is particularly devastating to economic growth because the disease strikes adults in their most productive years. Furthermore, in the early years the epidemic seemed to spread fastest among people with above-average education and skills, further sharpening the economic impact. HIV/AIDS is intimately connected to food security in a cyclical relationship. The consequences of food insecurity, specifically inadequate intake of calories and nutrients, render individuals more susceptible to HIV infection and cause them to progress faster from HIV infection to AIDS and, ultimately, to death. HIV/AIDS, in turn, hinders countries’ ability to achieve national food security through its effects on population and economic growth. For most of the African economies considered in this study, population growth rates are unlikely to fall below 2 percent by 2020, unless the onslaught of AIDS continues unchecked. Thus, it seems that AIDS will do relatively little, by way of reductions in population growth, to reduce the demand for food.