This literature and program review focused on the current and future role of microfinance and sustainable livelihood strategies in reducing adolescent girls' vulnerability to HIV infection in developing countries, particularly in sub-Saharan Africa. Part 1 of the review focuses on youth-centered programs to prevent HIV infection among vulnerable female adolescents--including microfinance and sustainable livelihood programs. Part 2 analyzes the relationship between microfinance and HIV prevention in the general population, with a focus on women and the oldest adolescents in the target group. Adapting the traditional microfinance model to meet the needs of this sub-group could prove to benefit not only these adolescents but also the microfinance industry.