Objective: The aim of this study was to examine how the ABO blood type affects endometrioid-type, EC prognosis. Method: A total of 522 patients diagnosed with EC between February 2010 and December 2021 were assessed, retrospectively. ABO blood types were used to divide the patients into four groups as A, B, O, and AB. Demographic data, menopause, prognostic variables, FIGO stage, and survival were evaluated. A in 217 patients, B in 84 patients, O in 181 patients, and AB blood type in 40 patients were analyzed. Results: Age, gravida, parity, body mass index, menopause, comorbidity, prognostic variables, FIGO stage, and survival according to the groups were similar (p > 0.012). Group A differed from other groups statistically in peritoneal fluid cytology (p = 0.004). B blood type had the best chance of cumulative overall survival, followed by AB, A, and O blood types, in that order (p = 0.170). Conclusion: In light of blood types sensitivity to endometrioid-type EC, O blood type has been identified as blood type with the highest risk of endometrioid EC.