Objective:To evaluate sonohysterography for the diagnosis of endometrial abnormalities in women treated with tamoxifen for breast cancer. Patients and methods:We assessed 37 women treated with tamoxifen for breast cancer who underwent sonohysterography and correlative endometrial biopsy for evaluation of postmenopausal bleeding or thickened endometrium greater than 8 mm. In 14 patients, endometrial biopsy was followed by endovaginal sonography to ensure removal of endometrial pathology. Sonohysterography findings were compared with histopathology results. Results:Sonohysterography findings coincided with histopathology results in 27 of 37 cases including 19 of 23 cases of endometrial polyps, 6 of 8 cases with thickened endometria and two cases had normal endometrium. Sonohysterography findings did not coincide with histopathology in 3 of the 14 cases who underwent endovaginal sonography after endometrial biopsy compared to 7 of the 23 cases who did not undergo such examination and 4 of these missed 7 cases were for endometrial polyps. Conclusion:Sonohysterography is a useful procedure for the diagnosis of endometrial abnormalities in tamoxifen-treated women. Endometrial abnormalities are better diagnosed on sonohysterography than on endometrial biopsy which has the limitation of some missed endometrial polyps, a problem that may be minimized by performing endovaginal sonography after endometrial biopsy. 2013 Production and hosting by Elsevier B.V. on behalf of Egyptian Society of Radiology and Nuclear Medicine.