Abstract: Objective To analyze the correlation between preoperative hypoproteinemia and the risk of perioperative allogeneic erythrocyte transfusion in ovarian cancer patients undergoing cytoreductive surgery. Methods Ovarian cancer patients who underwent cytoreductive surgery at Peking Union Medical College Hospital from January 2014 to December 2018 were retrospectively included. Clinical data such as the patients' general information, preoperative plasma albumin, American Society of Anesthesiologists classification, intraoperative bleeding volume, operation time, perioperative (intraoperative and within 3 d postoperatively) allogeneic red blood cell transfusion were collected, and the correlation between preoperative hypoproteinemia (plasma albumin＜35g/L) and the risk of allogeneic red blood cell infusion was analyzed by using multivariate Logistic regression. Results A total of 1001 ovarian cancer patients who met the inclusion and exclusion criteria were enrolled, of which 64 (6.4%) had preoperative hypoproteinemia and 481 (48.1%) received perioperative allogeneic red blood cell transfusion. The rate of perioperative allogeneic red blood cell transfusion was higher in the patients with hypoproteinemia than in those without hypoproteinemia 84.4% (54/64) vs. 45.6% (427/937), P＜0.001. Multivariate Logistic regression analysis corrected for confounders such as American Society of Anesthesiologists classification, intraoperative bleeding volume, and operative time found that preoperative hypoproteinemia was significantly associated with the risk of perioperative allogeneic red blood cell transfusion (OR=5.68, 95% CI: 2.56-13.57, P＜0.001). Conclusion : Preoperative hypoalbuminemia could be associated with the increased risk of perioperative transfusion in patients undergoing cytoreductive surgery for ovarian cancer.