5577 Background: Perioperative red blood cell transfusion (PRBCT) may be a negative prognostic marker in surgical oncology. We assessed PRBCT as an independent risk factor for recurrence and death from epithelial ovarian cancer (EOC) in the largest cohort to date. Methods: Patient characteristics and process-of-care variables (NSQIP-defined, >130 variables) were retrospectively abstracted from 587 women who underwent primary staging and cytoreduction for EOC (1/1/03-12/29/08). Evaluated using propensity scoring with univariate logistic regression and odds ratios (OR) and Cox proportional hazards regression and hazard ratios (HR). Factors with p<0.1 used in multivariate models. Results: Rate of PRBCT was 77.0% (452/587). In univariable analysis, PRBCT was associated with older age (OR 1.25[95% CI 1.06, 1.48]/10yr increase), stage≥IIIa (4.66[3.04, 7.13]), splenectomy (26.63[3.67, 193.17]), higher surgical complexity (1.86[1.17, 2.95] score 2; 21.48 [7.37, 62.59] 3; referent 1), serous histology (2.36[1.57, 3.55]vs non-serous), longer operating time (1.58[1.36, 1.83]/hr increase), and residual disease (3.26[1.97, 5.41]≤1cm; 1.97[1.09, 3.56]>1cm), and lower preop hemoglobin (Hb) (1.89[1.59, 2.27]per 1g/dL decrease). In univariable analysis, PRBCT was associated with a higher risk of recurrence (HR 1.96[95% CI 1.43, 2.68]) and death (1.71[1.28, 2.28]). However, in multivariable analysis, stage≥IIIa (4.03[2.05, 6.49]), splenectomy (1.41[1.02, 1.95]), residual disease (1.86[1.41, 2.46]≤1cm; 2.91[2.02, 4.18]>1cm), and lower preop Hb (1.09[1.01, 1.19]) were associated with higher risk of recurrence. Older age (1.24[1.12, 1.37]), stage≥IIIa (3.07[1.93, 4.90]), albumin ≤3 g/dL (2.06[1.28, 3.31]), residual disease (1.63[1.22, 2.19]≤1cm; 3.03[2.19, 4.18]>1cm), and low Hb (1.08[1.00, 1.19]) were associated with higher risk of death. Serous histology (0.70[0.52, 0.95]) associated with lower risk of death. Conclusions: PRBCT does not appear to be directly associated with disease-free and overall survival in EOC. Lower preoperative Hb was associated with a higher risk of both recurrence and death. The need for PRBCT appears to be a stronger prognostic indicator than the receipt of PRBCT.