In order to assess the pathophysiology of gonadotropin secretion in patients with idiopathic precocious puberty, responses of LH and FSH to LH-releasing hormone (LH-RH), clomiphene citrate (Clomid) and medroxyprogesterone acetate (Deop-provera) in 6 female patients were tested. The basal levels of serum LH and FSH were elevated in 4 of 6 patients and enhanced LH response to 100 mug of intravenous LH-RH was observed in 5 patients, while FSH response was comparable to that of prepubertal subjects. Administration of Clomid (50 mg) for 7 days provoked LH increase in 3 out of 6 patients in contrast to no LH change found in normal prepubertal girls. while FSH levels decreased in 3 out of 6 patients. Intramuscular injection of Depo-Provera (100 mg) reduced LH and FSH levels in 4 patients. The Depo-Provera therapy in a dose of 75 approximately 225 mg every two weeks, caused suppression of breast development and menstrual bleeding but the prevention of growth spurt and bone age maturation were insufficient. Basal body temperature charts in 2 patients showed an ovulatary pattern immediately following cessation of Provera therapy of more than 8 years' duration. In conclusion, it is suggested that 1) function of hypothalamo-pituitary-ovarian system in patients with idiopathic precocious puberty is similar to that of normal pubertal subjects, 2) therapeutic doses of Depo-Provera, enough to suppress the patients' secondary sex characterics, was not sufficient to control bone age maturation 3) it is necessary to follow up patients more closely by measuring serum levels of gonadotropin and estrogen during the course of therapy.