Gonadal hyperfunction is the most frequent endocrine dysfunction in females with McCune-Albright syndrome (MAS). Peripheral precocious puberty is usually the first MAS manifestation in children, characterized by episodes of hypersecretion of estrogens with a consequent reduction in gonadotropin secretion. Little is known about the course of this endocrine disease in adolescence and during young adult life. The aim of this study was to evaluate ovarian function in 10 females with MAS (age 11.4-20.1 years) to detect the persistence of autonomous ovarian hyperfunction throughout and following adolescence, after at least 1 year wash out of any treatment for precocious puberty. LH, FSH, estradiol, prolactin, androgen secretion, ovarian and breast sonography in luteal and follicular phases of some menstrual cycles were evaluated. We demonstrated the persistence of some ovarian autonomy, documented by hyperestrogenism and/or low or absent gonadotropin secretion and/or ovarian cysts.