Background: Morbid obesity presents a challenge in providing standard treatment in endometrial cancer (EC). We aim to evaluate the impact of morbid obesity on treatment and survival outcomes in women with EC. Methods: Patients diagnosed with EC from 2005–2015 were stratified by body mass index (BMI ≥40 kg/m2 vs. <40 kg/m2) and low risk (LR) and high risk (HR) subgroups based on stage, grade, myometrial invasion and histology. Demographics, tumor characteristics and treatment-related outcomes were analyzed. Univariate, multivariable and propensity-weighted Cox models were used to evaluate progression free survival (PFS) and overall survival (OS). Results: Of 1778 evaluable patients, those with BMI ≥40 kg/m2 were significantly younger, more likely endometrioid histology, lower grade, earlier stage, myometrial invasion <50%and absent lymph-vascular space invasion (LVSI). A similar proportion of patients with BMI <40 and ≥40 kg/m2 in LR and HR groups received radiation and chemotherapy. However, morbidly obese patients were less likely to undergo lymphadenectomy in both risk groups (p = 0.012 and p = 0.009, respectively). On propensity-weighted analysis, there was no significant difference in PFS or OS between patients with BMI <40 and ≥40 kg/m2 (HR 0.89, 95% CI (confidence interval) (0.60, 1.30) and HR 0.74, 95%CI (0.49, 1.12) respectively). Conclusions: Morbid obesity is associated with favorable prognostic factors in EC patients. When stratified by risk group, morbidly obese patients receive similar postoperative treatment but are less likely to undergo lymphadenectomy. PFS and OS are similar between patients with BMI <40 and ≥40 kg/m2 when risk groups and propensity score matching are considered.