In 1956, Prader and Willi1first described a clinical syndrome that included severe neonatal hypotonia, early childhood hyperphagia, obesity, diabetes, hypogonadism, cryptorchidism, dental caries, and mental deficiency. Since this initial report, more than 100 additional cases have been reported,2–6and several reviews have appeared.7.8Although the true incidence of the syndrome is not known, the Prader-Willi syndrome (PWS) may be at least as common as trisomy-21 (mongolism).9Because diagnosis of this relatively new syndrome will be made with increasing frequency, and because PWS has several features of concern to the anesthesiologist, this case report and discussion are presented to aid others in planning anesthesia for these patients.