Anemia is prevalent in patients with gynecologic cancers and is associated with increased peri-operative morbidity. We aimed to characterize risk factors for pre-operative anemia and describe outcomes among patients undergoing surgery by a gynecologic oncologist to identify potential areas for impactful intervention. We analyzed major surgical cases performed by a gynecologic oncologist in the National Surgical Quality Improvement Program (NSQIP) database from 2014 to 2019. Anemia was defined as hematocrit <36%. Demographic characteristics and peri-operative variables for patients with and without anemia were compared using bivariable tests. Odds of peri-operative complications in patients stratified by pre-operative anemia were calculated using logistic regression models. Among 60 017 patients undergoing surgery by a gynecologic oncologist, 23.1% had pre-operative anemia. Women with ovarian cancer had the highest rate of pre-operative anemia at 39.7%. Patients with advanced-stage cancer had a higher risk of anemia than early-stage disease (42.0% vs 16.3%, p≤0.001). In a logistic regression model adjusting for potential demographic, cancer-related, and surgical confounders, patients with pre-operative anemia had increased odds of infectious complications (odds ratio (OR) 1.16, 95% CI 1.07 to 1.26), thromboembolic complications (OR 1.39, 95% CI 1.15 to 1.68), and blood transfusion (OR 5.78, 95% CI 5.34 to 6.26). There is a high rate of anemia in patients undergoing surgery by a gynecologic oncologist, particularly those with ovarian cancer and/or advanced malignancy. Pre-operative anemia is associated with increased odds of peri-operative complications. Interventions designed to screen for and treat anemia in this population have the potential for significant impact on surgical outcomes.