Anorexia nervosa and bulimia nervosa are common disorders in the pediatric population. This article is designed to help the clinician develop a detailed understanding of these disorders as they affect children and adolescents. The etiology, diagnosis, complications, and treatment of these eating disorders are discussed. The special circumstances of diabetes mellitus, athletics, and the interface with the obese patient also are covered. The need to correctly identify a patient with the disorder, perform the appropriate testing, and organize the most appropriate treatment is required from virtually every primary care practitioner.