The chronically ill child presents many difficult challenges for all health care providers, including dentists. With 10-20% of all children in the United States having one or more chronic diseases or impairments, the lack of availability and utilization of dental services for this population group has been described as catastrophic. Barriers to essential care include the medical problem itself, dental school curricula, economics, apathy, and a lack of coordination of services between physicians, allied health care providers, and dentists. A number of common chronic illnesses and their specific dental treatment ramifications and requirements are discussed in detail. A thorough understanding and utilization of this information are essential for maximizing the quality and quantity of life for these special patients.