Prader-Willi syndrome (PWS) is a rare, heterogeneous genetic disorder characterised by hyperphagia leading to life-threatening obesity, cognitive problems, and numerous behavioural disturbances such as temper tantrums, stubbornness, manipulative behaviour, and obsessive-compulsive characteristics. Clinical symptoms involve severe hypotonia and feeding difficulties in early infancy, characteristic facial features, hypogonadism, and multiple endocrinological disturbances. PWS is caused by an absence of expression of imprinted genes in the paternally derived PWS region (i.e. 15q11-q13). About 70% of PWS cases result from de novo deletions. Nowadays, the clinical picture of Prader-Willi syndrome is changing due to diagnosis in early infancy and prompt prevention and treatment of obesity. Hence the issue of behavioural disturbances has become the main challenge in PWS management. Individuals with Prader-Willi syndrome need multispecialty medical care. Amongst numerous clinical trials targeting the main symptoms of PWS, the only effective and approved regimen is growth hormone treatment.