This presentation given by the Stanford Gender-Based Violence Prevention Collaborative presents a matched-set, cluster-randomised trial of upper-primary students in the unplanned settlements around Nairobi, Kenya. The intervention features parallel boys and girls curriculums delivered in a classroom environment. There are six sessions, two hours per session, featuring group-based, roleplaying and situational practice. The girls’ program is a four-pronged approach: empowerment, situational awareness, verbal skills, physical self-defense skills. Boys’ program focuses on positive masculinity and, for older adolescents, includes bystander-intervention training.