Prader-Willi syndrome is a genetic illness associated with a defect on
chromosome 15. It presents with hypotonicity in infancy followed by v
oracious appetite and gross obesity from early childhood and with a ra
nge of other clinical and behavioural sequelae. This case report is of
an adolescent boy who was admitted to a psychiatric unit for an inten
sive behavioural programme to control his weight gain and deal with as
sociated behavioural problems, and demonstrates that an inpatient prog
ramme can lead to sustainable improvements in weight control and other
indicators of well-being in PWS patients.