While the quality of health care has a powerful influence on the well-being of infants and children, little information is available about the medical services received by children. This Dartmouth Atlas report examines small area variations in childrenÕs health care in one region of the United StatesÑNorthern New EnglandÑand shows the patterns of care received by children for ambulatory physician services, hospitalization, common surgery, imaging, and outpatient prescription fills. The findings from this report show marked variation in care across the region. While there are many examples of excellent care, the findings raise troubling questions about whether the medical practice patterns reflect the care that infants and children need and that their families want.