Background: Postmenopause is defined as the permanent cessation of menstruation for one year due to failure of the ovarian follicular activity. Objective: This work aimed to study the role of endometrial thickness measured by transvaginal sonography in the detection of endometrial carcinoma in women with postmenopausal bleeding. Patients and Methods: A cross-sectional study was conducted on 120 women with postmenopausal bleeding admitted to the Obstetrics & Gynecology Department at Zagazig University hospitals through the period from September 2018 to September 2019. All cases were subjected to full history, full clinical examination, transvaginal sonography, and diagnostic endometrial biopsy which was taken for histopathological examination. We exclude premenopausal women and postmenopausal patients in HRT. Results: This study showed TVS evaluation of ET of the studied cases ranged from 1 to 20 mm with a mean of 9.65 mm. Also, 48.3% of the cases had endometrial thickness more than 10 mm, 34.2% had less than 5 mm, and 17.5% had from 5 to 10mm.that 34.2% of the studied cases had atrophic endometritis, 26.7% had an endometrial polyp, 17.5% had simple hyperplasia, 7.5% had atypical hyperplasia and 14.2% had endometrial adenocarcinoma. Conclusions: Transvaginal sonography evaluation of endometrial thickness is not sensitive enough to detect cancer of the endometrium and therefore couldn't replace histological evaluation of the endometrial tissue in women with postmenopausal bleeding.