As more funding becomes available for HIV/AIDS programs in developing countries, an understanding of how prevention interventions lead to behavioral change and how behavioral change leads to reductions in HIV prevalence is crucial. This study presents the results of an extensive effort to develop a matrix to relate coverage of key HIV/AIDS-prevention services to changes in behavior among different risk groups and to describe the gaps that exist in the literature. Many studies could not be included in the matrix because they did not meet the necessary criteria. Evaluation of interventions targeting abstinence programs, workplace programs, and certain groups at high risk of infection would prove invaluable.