Objective: To compare the rate of anastomotic leakage in patients treated with posterior pelvic exenteration for advanced ovarian cancer, regardless of whether or not a systematic ileostomy was performed.. Secondary objectives include surgical and oncologic outcomes. Method: This is an observational retrospective, multicenter study comparing two cohorts of patients managed for advanced stage ovarian cancer in two French cancer centers, from January 2019 to February 2023. All patients underwent cytoreductive surgery with colorectal resection and immediate colorectal anastomosis. Protective ileostomy could be performed in a center (center A) whereas it was never done in the other one (center B). Results: A total of 122 patients were included (54 patients in center A and 68 patients in center B). Protective ileostomy was performed in 64,9% of cases in center A. All seven anastomotic leakage concerned center B (10.3%; p=0.017). Occurrence of complications between center A and center B are similar (p=0.65). Grade 3 complications were more frequent in center B. We observed higher rate of incomplete cytoreduction in center A (p=0.04). Survival analyses do not show significative difference between center A group and center B group, for OS (p=0,32) and DFS (p=0,41). Conclusion: Performing a protective ileostomy is an effective way to prevent anastomotic leakage in cytoreduction surgery of advanced ovarian cancer. However, there is no clear evidence in term of long-term oncologic outcome and a broad policy of this procedure exposes to specific morbidity that can negatively affect the patient’s prognostic.