<h3>Objectives:</h3> Women with early-stage endometrial cancer (EC) are twice as likely to die of cardiovascular disease than their cancer. For this reason, more emphasis needs to be placed on weight management in early-stage EC to decrease morbidity and mortality in that population. Bariatric surgery has sustainable effects on weight loss and comorbidity improvement. That the primary approach to managing early-stage EC is laparoscopic hysterectomy (LH) presents an opportunity to perform simultaneous bariatric surgery. As this combined surgery is rarely performed, a potential opportunity to address the true underlying problem is missed. We aimed to study the cost-effectiveness of the combined procedure in comparison to LH alone. We performed a cost-effectiveness analysis of combined LH with bariatric surgery (combined surgery) to assess the lifetime costs and quality-adjusted life years (QALYs) in EC survivors with obesity-related disease (ORD). <h3>Methods:</h3> The study population was obese women aged 50-59 with ORD (hypertension and diabetes) undergoing surgery for atypical endometrial hyperplasia or early stage EC. A decision-analytic model with lifetime horizon was constructed to compare combined surgery to LH alone. Following surgery, 17 health-state Markov models consisting of no ORD, any combination of the four ORDs, and all four ORDs were used to estimate life expectancy and lifetime healthcare costs. Annual probabilities and healthcare costs for normal weight, overweight, and obese women were estimated using nationally representative data from the 2008-2016 Medical Expenditure Panel Survey. Utility weights were obtained from published studies and used to discount life expectancy estimates to calculate QALYs. Surgery costs for combined surgery were obtained from Washington University in St. Louis. Surgery costs for LH and surgical complication costs were obtained from published studies. Costs were evaluated from the healthcare sector perspective and presented in U.S. dollars at the 2020 price level based on the Medical Care Component of the Consumer Price Index for All Urban Consumers. Future costs and QALYs were discounted to present values using an annual rate of 3%. <h3>Results:</h3> Life expectancy after combined surgery was 30.69 years and 16.56 QALYs compared to 23.96 years and 11.47 QALYs for LH. The lifetime healthcare cost for patients with combined surgery was $130,366 compared to $267,742 for patients with LH alone. In terms of cost-effectiveness, LH was dominated by combined surgery, because combined surgery was more effective and less costly. <h3>Conclusions:</h3> This study is the first to conduct a cost-effectiveness analysis comparing LH to combined LH and bariatric surgery in obese women with ORD undergoing surgery for early-stage EC. Combined surgery is cost-saving and should be considered as a treatment option for this population. Further study of improving access to combination surgery is warranted.