To relate the changing epidemiology of childhood to current patterns of pediatric practice in the United States, a critical literature review and selected analyses of national datasets, including the National Health Interview Survey, the National Hospital Discharge Survey, and National Vital Statistics System, were conducted. Trends over the past several decades suggest that the incidence of serious acute illness in children has fallen while the prevalence of chronic disease has risen. These trends have resulted in a growing concentration of serious childhood morbidity and mortality into chronic disorders. Current pediatric practice structures appear to be poorly suited to meet the growing demands of chronic disease in children and likely will require major reform in organization, financing, and training.