Prader-Willi syndrome (PWS), a complex genetic disorder, arises from suppressed expression of paternally inherited imprinted genes on chromosome 15q11-q13. Characteristics include short stature, intellectual disability, behavioral problems, hypogonadism, obesity, and reduced bone and muscle. The life expectancy of persons with PWS has increased in recent years. Cardiovascular diseases, diabetes, dermatological, and orthopedic problems are common physical complaints in older people with PWS. Behavioral problems are major concerns in adults with PWS into old age. And aging is also associated with significant social and economic changes. Age-related physical morbidity, physical appearance, behavioral and psychiatric problems, functional decline and economic problems can be combined in older PWS. The care for older people with PWS requires a life span approach that recognizes the presence, progression, and consequences of specific morbidity.