This publication was developed in response to requests by prevention service providers and planners, for science-based interventions that work in HIV/AIDS prevention. All interventions came from behavioral or social studies that had both intervention and control/comparison groups and positive results for behavioral or health outcomes. The document summarizes each intervention that met all criteria. All interventions have been highly effective with a variety of populations (clinic patients, heterosexual men and women, high-risk youth, incarcerated populations, injection drug users, and men who have had sex with men). They have been delivered to individuals, groups, and communities in settings like storefronts, gay bars, health centers, housing communities, and schools. A table highlights population and intervention characteristics for each intervention. Another table indicates interventions that are part of the Centers for Disease Control and Prevention's Replicating Effective Programs, Prevention Counseling Course Series, and Research to Classroom: Programs That Work projects. These ongoing projects support development of intervention materials, training, and technical assistance. Each intervention summary presents title, authors, and reference; intervention goals and setting; population; comparison condition; intervention description; findings, and contact person. An appendix describes in detail the criteria used to select the interventions. (Contains 50 references.) (SM)