Assessing child health is critical to a variety of child health, educational, and social programs, as well as to clinical research and practice. However, despite the apparent wealth of measures available in health, education, and legal and social welfare systems, little agreement exists as to what are the most important measures and for what domains of health. Development of improved measures may capitalize on advances in conceptualization of child health, including the dynamic nature of the interplay of child health and development over time. The need for enhanced measures can be illustrated by consideration of various aspects of pediatric care: well-child care, acute illness care, and the management of children with special health care needs. In particular, the strong theoretical perspectives on aspects of development such as cognition and behavioral development need to be informed by the experience of various states of health and their developmental implications. If generalist academicians are to further their research and educational mission, they must engage, and urgently, in the development and measurement of child health.