We assessed the usefulness of revised Bethesda System reporting of exfoliated benign endometrial cells (EMs) in postmenopausal women. Cervicovaginal cytology specimens with benign EMs in postmenopausal women and "out-of-phase EMs" in premenopausal women 40 years and older were identified. Cases with histologic follow-up within 12 months were selected. There was tissue follow-up for 130 postmenopausal women: 10 (7.7%) had significant findings (endometrial adenocarcinoma, 6 [2 (33%) in asymptomatic women]; complex atypical endometrial hyperplasia [CAH], 3; leiomyosarcoma, 1); 20 were receiving hormone replacement therapy (HRT; n = 15) or tamoxifen (n = 5); 2 (10%) had significant pathology (endometrial adenocarcinoma, 1; CAH, 1). Eight not taking hormones (7.3%) had significant pathology (adenocarcinoma, 5; CAH, 2; leiomyosarcoma, 1). There were follow-up data for 96 premenopausal women; only 1 (who had vaginal bleeding) had significant pathology (CAH). The difference in incidence of preneoplastic and neoplastic conditions after a cytologic interpretation of "benign EM" between postmenopausal and premenopausal women was significant (P pound .025); There was no difference between postmenopausal women receiving or not receiving HRT (P > .05). Reporting benign EMs for premenopausal women 40 years and older has no clinical significance but does for postmenopausal women, regardless of HRT and symptoms.