OBJECTIVE: To evaluate the prevalence of premalignant and malignant polyps and their association with menopausal status, hormone therapy and clinical characteristics in perimenopausal and postmenopausal women. METHODS: A surgical database was used to select pre- and postmenopausal women >or=40 years of age, submitted to hysteroscopic resection of endometrial polyps. The medical records of 475 women were reviewed and clinical characteristics and histological diagnosis of resected polyps were assessed. RESULTS: The majority of women had benign endometrial lesions, 78.53% of which were endometrial polyps and 13.47% polyps with simple or complex endometrial hyperplasia without atypia. Polyps with endometrial hyperplasia with atypia comprised 1.05% of cases, while 2.74% were carcinomatous polyps. Analysis using prevalence ratios showed that premalignant and malignant lesions were associated with age and postmenopausal bleeding. Women >60 years of age had a prevalence ratio 3.28 times greater (95%CI: 1.19-9.07) of premalignant or malignant polyps. When only postmenopausal women were evaluated for the effect of age, those over 60 years of age had a prevalence 5.31 times greater (95%CI: 1.22-23.09), while those with postmenopausal bleeding had an age-adjusted prevalence ratio of 3.71 (95%CI: 1.21-11.34) compared to asymptomatic women. No significant association was found between arterial hypertension, diabetes mellitus, obesity, use of hormone therapy or tamoxifen and premalignancy or malignancy. CONCLUSIONS: There was a low prevalence of premalignant and malignant lesions in endometrial polyps. Older women and those with postmenopausal bleeding had a greater prevalence of malignancy and in these cases hysteroscopic resection of endometrial polyps is mandatory.