To investigate the diagnostic accuracy of endometrial curettage in patients with endometrial carcinoma. In this retrospective study, pre-and postoperative histopathologic findings of patients with endometrial cancer were investigated. 168 patients with the final diagnosis of endometrial cancer were enrolled in the study. Pre-and postoperative histopathologic diagnoses and grades (according to the 1988 FIGO classification) of the patients were compared retrospectively. 22 patients were diagnosed as having endometrial hyperplasia and the remaining 136 patients had endometrial carcinoma preoperatively. Overall discrepancy rate of grades was 39%(31% upgrade, 8% downgrade; p< 0.05). There was also 9% discrepancy between the pre-and postoperative histopathological types. It has been suggested that since endometrial cancer patients with low grades according to the preoperative pathologic diagnosis have a potential to upgrade, the management of these patients if myometrial invasion is less than one-half thickness, simply by hysterectomy plus bilateral salpingo-oophorectomy (without lymph node sampling), might actually miss some patients who actually deserve surgical staging. Further studies are needed to draw a sufficient conclusion.