Restless Development's youth-led model places trained Volunteer Peer Educators (VPEs), aged 18-25 years, in schools to teach HIV prevention and reproductive health (RH). VPEs also run youth centers, extracurricular and community-based activities. This evaluation assesses program effects on students' HIV/RH knowledge, attitudes and behaviors using a non-randomized quasi-experimental design among 2133 eighth and ninth grade students in 13 intervention versus 13 matched comparison schools and program costs. Intervention students had significantly higher levels of knowledge related to HIV [odds ratio (OR) 1.61, 95% confidence interval (CI) 1.18-2.19; P < 0.01] and RH (OR 1.71; 95% CI 1.21-2.49; P < 0.01), more positive attitudes toward people living with HIV and greater self-efficacy to refuse unwanted sex and access condoms. No evidence of differences in ever having had sex was found (28% in the intervention; 29% in the comparison schools). However, intervention students were more likely not to have had sex in the previous year (OR 1.26, 95% CI 1.03-1.56; P < 0.05) and to have had only one sex partner ever (OR 1.43, 95% CI 1.00-2.03; P < 0.05). The average annual cost of the program was US$21 per beneficiary. In conclusion, the youth-led model is associated with increased HIV and RH knowledge and self-efficacy and lowered levels of stigma and sexual risk-taking behaviors.