This article makes the case that there has been insufficient global attention to the health and development of children in the second decade of life. The author uses her vantage point of UNICEF to identify that institution's history of accomplishments for younger children and the opportunity to increase its work on adolescents, in collaboration with the research community. She notes that evidence-based programs for adolescents have the potential to consolidate global gains in early and middle childhood, such as reductions in under-five mortality and gains in improving access to and quality of primary schooling, safe water, and routine immunizations. A distinct opportunity in working with this older cohort is the potential for engaging adolescents as social actors in their communities. (Contains 2 figures.)