The last century witnessed dramatic changes in the practice of health care, and coming decades promise advances that were not imaginable even in the relatively recent past. Science and technology continue to offer new insights into disease pathways and treatments, as well as mechanisms of protecting health and preventing disease. Genomics and proteomics are bringing personalized risk assessment, prevention, and treatment options within reach; health information technology is expediting the collection and analysis of large amounts of data that can lead to improved care; and many disciplines are contributing to a broadening understanding of the complex interplay among biology, environment, behavior, and socioeconomic factors that shape health and wellness. On February 25-27, 2009, the Institute of Medicine (IOM) convened the Summit on Integrative Medicine and the Health of the Public in Washington, DC. The summit brought together more than 600 scientists, academic leaders, policy experts, health practitioners, advocates, and other participants from many disciplines to examine the practice of integrative medicine, its scientific basis, and its potential for improving health. This publication summarizes the background, presentations, and discussions that occurred during the summit. –Executive summary.