Background/aim: The purpose of this study is to investigate the prognostic significance of lower uterine segment (LUS) involvement in endometrial cancer (EC). Materials and methods: We reviewed the patients who were operated at our institution between July 2007 and March 2015 with the diagnosis of EC. Tumors localized in the corpus and involving the LUS or localized entirely in the LUS formed Group A, while tumors in the uterine corpus without LUS involvement formed Group B. Clinicopathological characteristics and survival of the patients were compared in both groups. Results: A total of 500 patients were included in the study. There were 139 patients who had tumors involving the LUS and formed Group A, while 361 patients with endometrial tumors in the uterine corpus without LUS involvement formed Group B. We did not detect a significant difference between survival of the patients in group A and group B (78 months vs. 87 months, respectively; P > 0.05). Conclusion: We found that LUS involvement was not an independent prognostic factor for poor survival, but it is associated with other poor prognostic factors such as deep myometrial invasion, uterine serosal involvement, lymphovascular space invasion, lymph node metastasis and higher FIGO grade.