One approach in HIV prevention programming targeting youth is to use peer leaders in what is referred to as peer education programming. This paper critically reviews and synthesizes the results and lessons learned from 24 evaluated peer-led programs with an HIV/AIDS risk reduction component that target youth in the communities where they live and are delivered in low- and middle-income countries. Interventions were identified through a comprehensive search of the peer reviewed AIDS-related literature as well as publication lists of major organizations in the UN family that address HIV and AIDS. Our synthesis of study results finds that these programs have demonstrated success in effecting positive change in knowledge and condom use and have demonstrated some success in changing community attitudes and norms. Effects on other sexual behaviors and STI rates were equivocal. We include an overview of characteristics of successful programs, a review of program limitations, and recommendations for the development and implementation of successful community-based peer-led programs in low-income countries. (Contains 5 tables.)