PROJECT SUMMARY/ABSTRACT Urban minority youth, particularly African Americans, are disproportionately affected by HIV/AIDS and other sexually transmitted infections (STIs) (CDC, 2007a, 2007b, 2008a). Although early adolescence is a valuable window to focus prevention efforts, there are relatively few evidence-based HIV prevention interventions for middle school youth that have been tested and found effective in school settings. Consistent with the objectives of the NICHD RFA, the proposed study is designed to address these gaps by developing and testing a new theory-based intervention for urban, minority, middle school youth that builds on essential elements of sexuality development, sexual risk behavior prevention, and positive youth development. The proposed study will assess the effects of two theoretically based intervention components that aim to promote relationship development as an avenue of reducing sexual risk taking behaviors: (1) a skills- and norm-based HIV, other STI, and pregnancy prevention curriculum that will focus on relationships and related behaviors that may affect disease risk, such as developing healthy relationships, sexual partnering (e.g., multiple and concurrent partners), relationship norms (e.g., when to have sex in relationships), condom use and HIV/STI testing within relationships, and ending unhealthy relationships; and (2) a school-wide social norms component that will feature monthly peer-led activities (some delivered via electronic media) to permeate the school environment with pro-social norms regarding healthy relationships--reinforcing and extending the potential effects of the classroom curriculum, and providing positive models for other youth. The program will be evaluated to determine its efficacy in altering behavioral intentions and sexual risk taking behaviors (e.g., sexual initiation, number and type of partners, condom use) and related determinants, such as functional knowledge, attitudes, beliefs, perceived norms, parent-child communication, sexual limits, and awareness of risky situations. The evaluation will feature a randomized controlled design involving 10 schools (approximately 1,500 students). Five schools would receive the intervention; the other five would serve as comparison sites. Students would be assessed 3 times during the study--baseline, 6 and 18 months, using self report surveys administered with audio-enhanced personal digital assistants (APDAs). The proposed study would be among the first to evaluate an HIV prevention program for middle school youth that features relationships as a core theme. Further, resulting data would expand the limited literature on prevention activities for early adolescents; it would also add to a growing body of literature on adolescent relationship development, particularly among African American and other urban minority youth.