We report a case of a 66-yr-old woman with progressive hair balding, hirsutism and virilization. Gonadotropins and estradiol levels were in the postmenopausal range; total testosterone (TT), free testosterone (FT) and 17-hydroxyprogesterone (17-OHP) were elevated with dehydroepiandrosterone sulphate, androstendione and cortisol serum levels in the normal range, as 24-hr free urinary cortisol. TT, FT and 17-OHP were normalized, and FSH and LH fell to premenopausal levels on 18th day after a single i.m. injection of the GnRH analogue (GnRHa), triptorelin. Then, a diagnosis of hyperandrogenism of ovarian origin was made and bilateral ovariectomy was performed. Histological study of gonadal tissue revealed diffuse stromal hyperplasia of both ovaries with occasional nests of luteinized cells. With immunoperoxidase techniques these cells stained positively for testosterone and progesterone. One month after surgery, androgen levels were normalized together with regression of most of the clinical signs of virilization. In conclusion, our patient showed a severe virilization developed after menopause; hormonal investigations suggested a gonadotropin dependent ovarian hyperandrogenism, confirmed by histological examination; the presence of luteinized cells in the ovarian stroma was responsible for hyperandrogenism, as confirmed by the immunoperoxidase technique.