Congenital lipoid adrenal hyperplasia (CLAH) is an autosomal recessive disorder characterized by impaired synthesis of adrenal and gonadal steroids. It was demonstrated that loss-of-function mutations in the steroidogenic acute regulatory protein (StAR) gene cause CLAH and that 46,XX patients with CLAH develop spontaneous puberty. We had reported that three 46,XX patients with CLAH had presented spontaneous puberty and one of the patients had developed life-threatening ovarian cysts, before the etiology of CLAH had been clarified. In the present study, we analyzed their StAR gene and demonstrated mutations. Endocrinological examinations of the patients revealed that serum LH and FSH levels and their responses to the LHRH stimulation were not exaggerated before the onset of puberty. Serum LH levels and its response to LHRH were increased during puberty, whereas serum FSH levels remained within the normal range. Serum estradiol increased after the administration of human menopausal gonadotropins in the pubertal patient, suggesting that the ovary might have another system than StAR to facilitate cholesterol transport into the mitochondria. Although the patients had menstrual cycles, they remained anovulatory, and the resultant increased secretion of LH was speculated to be responsible for the development of ovarian cysts.