This study examines the effectiveness of the Sexuality Education Initiative (SEI), a comprehensive, multi-component, rights-based sexuality education program developed and implemented by Planned Parenthood Los Angeles for high school students. The primary goal of the SEI is to improve the sexual and reproductive health of youth attending Los Angeles high schools. The SEI consists of four intervention components: (1) a 12-session gender-sensitive, rights-based, comprehensive sexuality education curriculum, (2) a peer education and advocacy component, (3) a parent education component, and (4) clinical services linkages. It is hypothesized that the 12-session classroom curriculum is more effective than a 3-session control sex education curriculum. It is also hypothesized that the full SEI package (all four components) is more effective than the control condition (control curriculum and clinical services only).