A deeper understanding of how structure and environment shape the sexual and reproductive health vulnerabilities of youths across a range of outcomes has implications for the development of successful policies and programs. We have discussed some of the key structural and environmental factors that influence the sexual and reproductive health of adolescents, particularly in low- and middle-income countries, and the importance of engaging adolescents in identifying solutions. We have highlighted 2 case studies that describe structural or environmental approaches to improving adolescent sexual and reproductive health and made recommendations to more systematically incorporate attention to structure and environment to improve global adolescent health.