This article, uses panel data related to 20 Tanzania regions and 8 years to estimate the direct and indirect effects of female primary education on HIV/AIDS rates. A recursive framework for education, income and infections is employed, based on two autoregressive equations that allow us to obtain dynamic estimates of effectiveness. We find that the indirect effect working through changes in income outweighs the direct positive effect of education on infections, implying that female education can be effective as an intervention to lower the disease in Tanzania. The estimates of effectiveness are then utilized to carry out a cost-benefit analysis of the education expenditures. The human capital approach is used to measure the benefits. Irrespective of the timing of the benefits and costs, and the discount rate alternatives we consider, our best estimates result in positive net-benefits, with benefit-cost ratios in the range 1.3–2.9.