The remarkable achievements of the Human Genome Project promise great opportunities for disease prediction, treatment, and prevention. In this paper, we discuss the continuum of genetic variation as medical practice begins to shift focus from the study of single genes (genetics) to the study of the entire genome (genomics). Pediatricians should anticipate an influx of genetic information and will need to become as facile in interpreting this type of predictive information as they are with other types of medical data, while recognizing the unique ethical, legal, and social implications of genetic testing in children. We discuss an approach to assist pediatricians in decision-making that emphasizes the need for knowledge about the analytic performance of genetic tests, their validity in predicting health outcomes, and the utility of the genetic information in improving health and preventing disease.