Aims. Current literature showed that breast cancer patients using tamoxifen have an increased risk of endometrial pathology. To investigate the different incidence of histological alteration of endometrium and their possible correlation with the following adjuvant treatment: tamoxifen (TAM), non-steroidal aromatase inhibitors (AIs) or no treatment (NT). Method. We reviewed retrospectively 970 breast cancer women who were referred to the Hysteroscopic Service of three Italian Centers (University of Messina, Gynecological Center “Nuova Villa Claudia” of Rome, “Regina Elena” National Cancer Institute of Rome) for vaginal bleeding or ultrasound indications. Results. Hysteroscopic and histological findings in the TAM, AIs and NT groups, respectively, included: atrophic/physiological endometrium in 48, 52 and 33.3% of cases; endometrial polyp in 40.4, 38 and 49.1% of cases; submucous myoma in 4, 3 and 5.2% of cases; simple hyperplasia in 5, 3 and 7.1% of cases; complex hyperplasia in 0.3% in TAM patients and 0.4% in NT cases, no case in AIs group; dysplasia in 0.3% of TAM patients and 0.4% of NT patients, no case in AIs group; and endometrial cancer in 2, 4 and 4.1% of cases; one case (0.4%) of endometrial metastasis from the breast cancer was registered in the NT group (Table 1). Conclusion. Our preliminary data analysis suggests that TAM is not likely to be associated with endometrial pathology in breast cancer patients. In conclusion, we suggest a gynecological follow-up for all breast cancer patients, regardless of the adjuvant treatment; in addition, we solicit future studies to confirm the TAM safety profile in breast cancer patients.