After considering the postmenopausal variations in the hypothalamic-hypophyseal-ovarian feed-back system, the Authors review the medical literature about ovarian and adrenal contribution to postmenopausal steroidogenesis. Comparisons are made between postmenopausal sex-hormone levels in controls and in endometrial cancer affected patients; estradiol is given the main attention: its higher level in cancer patients seems closely related to their higher mean weight; indeed, no estradiol level difference is found between patients and controls correctly matched as to the body weight. The possible role of estradiol in the pathogenesis of endometrial cancer is then discussed basing on data obtained from women affected with diseases generally considered to be estrogen dependent.