Objective: to compare the diagnostic accuracy of 3D transvaginal ultrasound in identifying endometrial lesions in comparison to hysteroscopy. Settings: Kasr Al-Aini Hospital. Materials and Methods: Three dimensional transvaginal ultrasonography was done followed by hysteroscopy for all cases (number=50). Data obtained were compared and analyzed to estimate the accuracy of 3D transvaginal ultrasound. RESULTS: Compared to Hysteroscopy, the sensitivity, specificity, positive predictive value, negative predictive values and total overall accuracy of Three dimensional transvaginal ultrasonography for total abnormal findings were 89.13%, 100%, 100%, 44.44% and 90% respectively. Conclusion: Three-dimensional transvaginal ultrasound is a sensitive method to evaluate the endometrial cavity lesions or abnormalities, before resorting to invasive procedures such as diagnostic hysteroscopy. But hysteroscopy allows direct visualization of the uterine cavity so it has can detect small localized intrauterine lesions which could be missed by vaginal ultrasound.