A case study focuses on the characteristics and physical management of a 15-year-old with Prader-Willi Syndrome, a birth defect associated with hypotonia, insatiable appetite, hypogonadism, central nervous system dysfunction, and abnormal growth and development . A literature review addresses studies dealing with behavior modification of obesity and continuous eating, nutrition counseling, and physical activity intervention. Interventions in the case study included those programed by trained personnel in the following service areas: adapted physical education, behavior modification, nutrition, nursing, dormitory living, social work, education, and speech and language. Data are reported for behavior, weight, and adjustment to physical activity. Analysis of data from the S's developmental and medical histories, continuous evaluations, previous staffing summaries, motor proficiency tests, exercise metabolism tests, progress reports and staff and parent survey forms revealed that the S made considerable progress in reaching her program goals. She was found to demonstrate most of the characteristics classic to the Prader-Willi population. Recommendations were made for programming. (CL)