In Prader-Willi syndrome (PWS) hypothalamic dysfunction is the cause of hormonal disturbances, such as growth hormone deficiency (GHD), hypogonadism, and delayed or incomplete puberty. Only a few cases of central precocious puberty (CPP) have been reported. We describe an 8.8-year-old PWS boy, with microdeletion of chromosome 15q, who developed CPP. On admission, height was 131.1 cm (+0.17 SD), BMI 26.2 kg/m(2), pubic hair (Ph) 2, and testis 4.5 ml. We found increased growth velocity (7 cm/year), high testosterone levels, pubertal response to GnRH test, and advanced bone age (10.6 years). An evaluation of growth hormone (GH) secretion revealed a deficiency. Pituitary MRI was normal. LHRH analogue therapy (Leuproreline 3.75 mg/28 days i.m.) was started at 8.9 years and discontinued at 11.3 years, when the patient had bone age of 13 years. During therapy, growth velocity, testosterone, FSH, and LH peak decreased significantly, with no pubertal progression. Growth hormone therapy (0.24 mg/kg/week) was started at 9.5 years and discontinued at 15.3 years because the patient had bone age of 17 years. After interrupting LHRH therapy the patient demonstrated spontaneous pubertal progression with pubertal gonadotropin and testosterone. At 16.3 years, height was 170 cm (-0.48 SDS), BMI 36.3 kg/m(2), Ph 4, testis volume 10 ml and there was a combined hypothalamic and peripheral hypogonadism hormonal pattern (normal LH even with low testosterone and undetectable inhibin B with high FSH). To our knowledge this is the fourth male patient with genetically-confirmed PWS demonstrating CPP and GHD and the first with a long follow-up to young adulthood.