Increasing recognition of the complexity and importance of social determinants of child health has changed dramatically the scope, direction, and purpose of pediatric research. Considered in the context of the evolving research on the role of the human genome in determining the functional status of children and adults, the increasing focus on the social determinants of health emphasizes the need for multidisciplinary collaboration in research endeavors. The changing roles of children and youths in developed societies will require an understanding of the complexity and impact of their social, economic, political, and cultural roles in society on health status and outcomes. Globalization, the shrinking scope of national governments, the growing irrelevance of national borders, and our inexorable march toward a more integrated and interdependent world will have health consequences that as yet are not understood. These factors set the stage for the coming century and form the backdrop against which the formulation of research priorities must be staged.