Approximately 15% of children experience a significant illness prior to age 18 years. For many of them, school absenteeism, substandard academic performance, and social problems ensue. When disorders affect the central nervous system, some suffer global developmental delays or selective neuropsychological deficits. As health service providers, school psychologists understand both the educational process and the ways in which childhood illnesses can impact it. This article argues that school psychologists' breadth of knowledge enables consultation with teachers about health-related classroom accommodations and communication between medical professionals and educators. Epilepsy and type 1 diabetes mellitus are two conditions associated with a risk of school problems. Using these two disorders as examples, this article outlines roles for school psychologists and provides specific guidance about how they can promote success among all students with chronic illnesses. (Contains 1 table. Resources for Practitioners is appended.)