A patient with 17 alpha-hydroxylase deficiency (17OHD) who continued to menstruate is reported. A 24-year-old woman who presented with hypertension, hypokalemia and irregular menses had increased plasma ACTH and mineralocorticoids without any increase in glucocorticoids or sex steroids, and a bilateral adrenal enlargement on abdominal X-ray CT. ACTH stimulation test revealed hyperresponse of the metabolites of the mineralocorticoid pathway and blunted or absent response of those of the glucocorticoid and androgen pathway. Almost all of the abnormalities disappeared after dexamethasone administration. While 17OHD is usually known to accompany hypergonadotropic hypogonadism, the patient continued to menstruate, though irregularly. Although human chorionic gonadotropin administration failed to induce response, basal plasma levels of ovarian steroid (estradiol) and gonadotropins as well as response to LHRH stimulation test were all normal. Thus, the clinical and biochemical features of this case is compatible with the partial deficiency of both adrenals and ovaries, being less severe in the latter. A further analysis especially at molecular level is needed to elucidate the basis for the heterogeneity of this disorder.