Objective: Routine pelvic and para-aortic lymphadenectomy up to the level of the renal veins is controversial in endometrial cancer as the complication rate and prolonging the operation time is considerable. Intraoperative frozen section analysis of the uterus is the mainstay for the decision of performing a staging lymphadenectomy. Preoperative estimation of myometrial invasion may be useful for surgical planning. Our objective is to assess the accuracy of preoperative transvaginal ultrasound for identifying myometrial invasion. Methods: 80 consecutive patients operated between August 2017 and December 2019 with a histologically confirmed diagnosis of endometrial carcinoma evaluated within two weeks before surgery by transvaginal ultrasound are the subject of this study. Myometrial invasion estimation is documented and intraoperative frozen section analysis and final pathologic diagnosis as the reference standard was recorded. Results: Preoperative TVUS had 76.5% sensitivity, 91.3% specificity, whereas frozen section analysis had 85.3% sensitivity and 93.5% specificity, and they correlate well with each other (P 0.01). Agreement between these two methods was substantial according to Cohen’s kappa index (\kappa) = 0.74 (P 0.01) and percentage of agreement was 88%. Increasing tumor diameter decreased the prediction accuracy of preoperative ultrasound (P 0.01). Conclusion: There is good correlation of preoperative transvaginal ultrasound with intraoperative frozen section analysis and final pathology results. The subjective assessment of transvaginal ultrasound can guide surgeons as a useful preoperative tool for preparing surgery