Adolescents are at risk for HIV primarily through their sexual behavior. A comprehensive prevention strategy includes a national HIV campaign based on social marketing principles; targeted social marketing, intensive skill building, and sexually transmitted disease control programs for youth at high risk; programs targeting institutions (e.g., school health clinics), providers, and parents; and interventions to identify and reduce risk acts among seropositive youth. The U.S. focus for HIV prevention has been single-session educational classes (an ineffective strategy) or intensive multi-session, small-group interventions for youth at high risk (demonstrated to increase condom use by about 30%). There is a need to expand the range, modalities, and dissemination of HIV prevention programs nationally, to recognize (especially by policymakers) limitations of abstinence programs, and to increase early detection of HIV among youth.