First five patients exemplify the results of treatment of the Prader-Willi syndrome with growth hormone. The patients began the treatment at the age of 2.1–9 years at the dose of 0.55 IU/kg b.w./week. The youngest girl was an underweight patient and the others were overweight patients at the age of 2.9 to 9 years with BMI of 2.8–5.7 SD. Authors observed body height, mass, BMI, skinfold thickness and abdominal and mid-arm circumferences evaluated by SD score. Results comply with studies abroad. A significant increase of growth rate and SDS of body height was proved already in the first year of therapy (BMI decreased from 4.8 to 1.7 SD), as well as the skinfold thickness and abdominal circumference. Significant differences were found among the patients. In the underweight patient the body mass and thickness of the skin fold slightly increased, but obesity which is typical for clinical picture at the given age, did not develop. In one boy and a girl from families, which collaborated well and observed the dietary measures, the parameters of nutritional state normalized during the therapy. In a boy with limited physical activity and a girl whose family did not collaborate well, the slight improvements were of transient character. Conclusion: The treatment with growth hormone improves the clinical state in most patients with PWS, improves the quality of their lives and the family as a whole. A successful therapy requires that dietary measures and physical regimen are observed.

        Key words: Prader-Willi syndrome, growth hormone, obesity, the skinfolds thickness