The aim of the project is to implement and rigorously evaluate an innovative adolescent HIV/STI prevention program involving school students, professional peer educators, teachers, parents, rural health clinics and the wider community, by means of a community randomized trial. Primary objective: To measure the effectiveness of an adolescent HIV prevention intervention delivered to secondary school students and the wider community in reducing the incidence of HIV-1, Herpes simplex virus type 2 (HSV2) and unintended pregnancy among the students. Secondary objectives: I) To use a combination of quantitative and qualitative research methods to explore the evolution of sexual behavior in adolescents in rural Zimbabwe. II) To assess the impact of the intervention on knowledge and attitudes regarding reproductive and sexual health, reported behavior, and measures of self-efficacy. III) To determine through rigorous process evaluation whether these programs are delivered as intended. IV) To refine and assess the validity of research instruments for measuring sexual behavior in Zimbabwean adolescents. V) To examine through rigorous process evaluation acceptability and feasibility of providing VCT in rural community settings. VI) To study the epidemiology of HSV2 infection among adolescents, and to measure the extent to which HSV2 facilitates acquisition of HIV infection. Trial Design: 30 communities (60 schools) will be randomly allocated to either early or deferred program implementation. The impact of the program will be measured in a cohort of 6,600 students aged >12 (median age 15), who will be followed for 4 years (median age 19). Participants will be surveyed at the start of the project, after 30 months and after 4 years. At each survey they will complete a questionnaire and provide a saliva sample (and females a urine sample). The impact of the program on cumulative incidence of HIV-1 and HSV2 infection, and unintended pregnancy as well as on reported sexual behavior will be determined. A detailed process evaluation of the program will be conducted to inform wider program implementation.