The Council implemented and rigorously evaluated the Adolescent Girls Empowerment Program (AGEP), which was designed to build the health, social and economic assets of vulnerable girls in Zambia. AGEP reached more than 11,000 girls in rural and urban locations in the country from 2013 to 2016 and was rigorously monitored and evaluated to understand what type of girls’ empowerment interventions work in Zambia, for whom, and at what cost. Using a cluster randomized controlled trial, this research assessed the effectiveness of four approaches: “Safe space” girls’ clubs (SS-only), which included health and financial education and life skills training during weekly girls group meetings led by young women mentors from the community; “Safe spaces” + health service vouchers (SS+HV), entitling girls to health services provided by public and private facilities in the community; “Safe spaces” + health vouchers + girl-friendly individual savings accounts (SS+HV+SA), developed in partnership with a Zambian financial institution; and a control site in which girls received none of the above interventions. Participating community areas were randomly assigned to one of four study arms to determine cause and effect between program treatment and outcomes.