Purpose: To evaluate the reliability and accuracy of intraoperative pathological findings, compared to permanent section (PS) and to understand contributions of frozen section (FS) to final staging in patients with endometrioid carcinomas. Methods: This is a retrospective analysis of 79 patients undergoing intraoperative FS and with endometrioid adenocarcinomas. Intraoperative pathological findings were compared with final results as to grade, depth of myometrial invasion (MI), cervical involvement, lymphovascular space invasion (LVSI) and stage. We also analyzed whether staging procedures like pelvic or para-aortic lymph node metastasis, peritoneal cytology and extension beyond of uterus were related to FS findings. Staging was based on the FIGO 2009. Results: FS results were agreement in 89.9 % for grade, 88.6 % for depth of MI, 100 % for cervical invasion, and 92.4 % for LVSI, compared with PS. On FS, 12, 16.6 and 44.4 % of specimens in stages of IA, IB and II became upstaged in final pathology, respectively. Of 79 cases, 5 (6.3 %) were upstaged to IIIC1, and 3 (3.8 %) were upstaged to IIIC2 because of lymph node metastasis. A significant relationship was detected between lymph node metastasis, and FS grades (p = 0.001), LVSI (p = 0.000), cervical invasion (p = 0.006) and MI (p = 0.001). Conclusion: We consider that intraoperative FS is a useful procedure to identify poor prognostic pathological factors. While grading, depth of MI, cervical stromal invasion and LVSI on FS are significant in predicting lymph node metastasis, the existence of cervical stromal invasion and LVSI should be considered more effective parameters in the identification of metastatic endometrial cancer risks.