The evaluation design involves two levels of randomization: First, all schools are randomized into one of two conditions: receiving all three SEI school wide components (peer, parent, clinical services) or receiving only one of these three school wide components (clinical services). Schools are randomized within matched pairs of demographically similar schools. Second, within each school, classrooms are randomized into one of two conditions: a basic 3-session sex education curriculum (control) or the 12-session SEI curriculum (intervention). Thus, all participating 9th grade students will receive at least three sexuality education curriculum sessions and access to on-site clinic services.