PURPOSE: Precocious puberty is defined as the onset of secondary sexual characteristics before 8 year of age in girls and 9 year in boys. The purpose of this study is to analyze the spectrum of diagnoses made in a consecutive group of children referred for signs of precocious puberty and evaluate the clinical and endocrinologic characteristics of patients with precocious puberty. METHODS: The charts of all 948 children referred for evaluation of signs of precocious puberty between January 2003 and June 2007 in several referral centers were reviewed. Clinical features including age of onset, presenting symptoms, yearly growth rate, bone age advancement, weight, height, and body mass index were analysed and endocrine investigations included basal and gonadotropin releasing hormone (GnRH)-stimulated levels of luteinizing hormone (LH) and follicle stimulating hormone (FSH) as well as sex hormones. RESULTS: Of the 948 children referred for signs of precocious puberty, 915 (96.5%) were female and 33 (3.5%) were male. The final diagnoses made were early puberty (39%), premature thelarche (31%), true precocious puberty (27%) and precocious pseudopuberty (1%). The increases in yearly growth rate and bone age advancement were significant in true precious puberty group (P<0.05). The height and weight standard deviation score were significantly increased in true precious puberty and premature thelarche group compared to the average level according to gender and age (P<0.05). Endocrinologic studies showed that the level of basal LH, basal estradiol and GnRH-stimulated peak LH, peak FSH, peak LH/basal LH, peak FSH/basal FSH, peak LH/peak FSH ratio was all significantly higher in true precicous puberty group and early puberty group when compared to premature thelarche group (P<0.05). Neurogenic true precocious puberty among true precocious puberty was more common in boys (3 out of 7, 42.8%) than in girls (27 out of 253, 10.7%). Endocrinologic studies did not show any difference between idiopathic precocious puberty and neurogenic precocious puberty. CONCLUSION: The result of this study showed the proportion of true precocious puberty among the children referred for early pubertal signs was rather high. Collectively assessing all available data including detailed history, growth records, physical findings, laboratory studies and radiological imaging is important in the evaluation of a child with concerns of early pubertal maturation. Foregoing extensive studies regarding incidence and causes of true precocious puberty should be needed.