Objectives: Obesity is a known independent risk factor for endometrial cancer that is continuing to increase in incidence throughout the United States. There is limited data on perioperative outcomes among women with endometrial cancer and obesity, especially in the era of increasing prevalence of minimally invasive surgery. We examined the association between obesity and perioperative outcomes in patients who underwent hysterectomy for uterine cancer. Methods: The National Surgical Quality Improvement Program (NSQIP) database was utilized to identify women with uterine cancer who underwent hysterectomy between the years of 2007 and 2018. Patients were classified into body mass index (BMI) groups: normal (<25), overweight (25-29.9), and obese (≥30). Analyses were also performed that stratified the obese BMI group into 30-39.9, 40-49.9, and ≥50. Multivariable logistic regression models were developed to determine clinical and demographic factors associated with perioperative morbidity and mortality. The associations between BMI group and route of hysterectomy and performance of lymph node dissection were examined using log-linear regression models. Results: A total of 42,075 endometrial cancer patients including 15.2% who were normal weight, 20.1% who were overweight and 64.8% who were obese were identified. Compared to normal BMI and overweight patients, obese patients were more likely to undergo minimally invasive hysterectomy (73.7% for obese, 72.0% for overweight, 71.6% for normal BMI; P=0.0018) and were less likely to have a lymph node dissection during surgery (53.3% for obese, 60.0% for overweight, 58.9% for normal BMI; P<0.0001). There were no differences in perioperative outcomes based on three BMI groups (normal, overweight, and obese with BMI ≥30). However, compared to women with normal BMI, those with BMI ≥50 were more likely to have any complications (6.8% vs 4.4%; aRR 1.30; 95% CI, 1.07-1.58), severe (Clavian IV) complications (3.3% vs. 1.8%; aRR 1.53; 95% CI, 1.15-2.04), readmission (6.8% vs. 4.4%; aRR 1.37; 95% CI, 1.12-1.66), and reoperation (2.4% vs 1.2%; aRR 1.76; 95% CI, 1.24-2.49). Perioperative mortality was not statistically different among any of the obese cohorts compared to those with normal BMI. Conclusions: Obese women with endometrial cancer who undergo hysterectomy are more likely to have minimally invasive procedures and less likely to have lymph node dissections. Those with BMI ≥50 are at higher risk for severe perioperative complications and reoperation. Obesity is a known independent risk factor for endometrial cancer that is continuing to increase in incidence throughout the United States. There is limited data on perioperative outcomes among women with endometrial cancer and obesity, especially in the era of increasing prevalence of minimally invasive surgery. We examined the association between obesity and perioperative outcomes in patients who underwent hysterectomy for uterine cancer. The National Surgical Quality Improvement Program (NSQIP) database was utilized to identify women with uterine cancer who underwent hysterectomy between the years of 2007 and 2018. Patients were classified into body mass index (BMI) groups: normal (<25), overweight (25-29.9), and obese (≥30). Analyses were also performed that stratified the obese BMI group into 30-39.9, 40-49.9, and ≥50. Multivariable logistic regression models were developed to determine clinical and demographic factors associated with perioperative morbidity and mortality. The associations between BMI group and route of hysterectomy and performance of lymph node dissection were examined using log-linear regression models. A total of 42,075 endometrial cancer patients including 15.2% who were normal weight, 20.1% who were overweight and 64.8% who were obese were identified. Compared to normal BMI and overweight patients, obese patients were more likely to undergo minimally invasive hysterectomy (73.7% for obese, 72.0% for overweight, 71.6% for normal BMI; P=0.0018) and were less likely to have a lymph node dissection during surgery (53.3% for obese, 60.0% for overweight, 58.9% for normal BMI; P<0.0001). There were no differences in perioperative outcomes based on three BMI groups (normal, overweight, and obese with BMI ≥30). However, compared to women with normal BMI, those with BMI ≥50 were more likely to have any complications (6.8% vs 4.4%; aRR 1.30; 95% CI, 1.07-1.58), severe (Clavian IV) complications (3.3% vs. 1.8%; aRR 1.53; 95% CI, 1.15-2.04), readmission (6.8% vs. 4.4%; aRR 1.37; 95% CI, 1.12-1.66), and reoperation (2.4% vs 1.2%; aRR 1.76; 95% CI, 1.24-2.49). Perioperative mortality was not statistically different among any of the obese cohorts compared to those with normal BMI. Obese women with endometrial cancer who undergo hysterectomy are more likely to have minimally invasive procedures and less likely to have lymph node dissections. Those with BMI ≥50 are at higher risk for severe perioperative complications and reoperation.