HIV/AIDS continues to take a tremendous toll on the populations of many countries, especially in sub-Saharan Africa. In some countries with high HIV prevalence rates, life expectancy has declined by more than a decade and in a few cases by more than two decades. Even in countries with HIV prevalence of around 5 percent (close to the average for sub-Saharan Africa), the epidemic can reverse gains in life expectancy and other health outcomes achieved over one or two decades.This volume highlights work conducted under the umbrella of a World Bank work program on "The Fiscal Dimension of HIV/AIDS," including country studies on Botswana, South Africa, Swaziland, and Uganda. It covers four aspects of the fiscal dimensions of HIV/AIDS: First, it aims for a comprehensive analysis of the fiscal costs of HIV/AIDS, with a wider scope than a costing analysis focusing on only the policy response to HIV/AIDS. Second, it embeds the analysis of HIV/AIDS costs in a discussion of the fiscal context, and interprets these costs as a quasi-liability, not a debt de jure, but a political and fiscal commitment that binds fiscal resources in the future and cannot easily be changed, and very similar to a pension obligation or certain social grants or services. Third, it develops tools to assess the (fiscal dimensions of) trade-offs between HIV/AIDS policies and measures that take into account the persistence of these spending commitments. Fourth, most of the fiscal costs of HIV/AIDS are ultimately caused by new infections, and this study estimates the fiscal resources committed (or saved) by an additional (or prevented) HIV infection. Building on these estimates, the analysis here is able to assess the evolving fiscal burden of HIV/AIDS over time.