In order to investigate the presence of established risk factors for endometrial carcinoma in postmenopausal patients with breast cancer and with tamoxifen-associated endometrial polyps we compared a group of 25 patients with tamoxifen-associated endometrial polyps with 25 tamoxifen-treated patients without endometrial polyps. No significant differences were found between both groups of patients in age, parity, time after breast cancer and after menopause, duration and daily and total cumulative dose of tamoxifen intake, body mass index and serum levels of luteinising hormone (LH), follicle-stimulating hormone (FSH), oestradiol (E2), progesterone, sex hormone-binding globulin (SHBG), tamoxifen and CA125. So far there is no evidence that these polyps are premalignant lesions.