Background: Esophagectomy is a complex operation associated with significant morbidity for even fit, healthy patients. Prior studies have utilized hand grip strength or muscle mass to predict postoperative esophagectomy outcomes. This study however, used skeletal muscle gauge (SMG), a CT-derived body composition measure, along with age, to classify patients into groups to summarize perioperative surgical mortality after minimally invasive esophagectomy. Methods: A total of 396 patients undergoing minimally invasive esophagectomy between 2010 and 2022 were identified. Preoperative CT scans at the L3 vertebral level were analyzed to calculate skeletal muscle gauge (SMG) as the product of skeletal muscle area and skeletal muscle density. Patient demographics, histology, treatment, and outcomes including anastomotic leak, pneumonia, prolonged ventilation, discharge destination, 30-day readmission, and 90-day mortality were collected. Patients were grouped into quartiles of SMG and by age (≥75 and <75 years). 90-day postoperative mortality for the high risk group in the bottom SMG quartile (Q1) was compared to the low-risk group in the top 3 quartiles (Q234). Results: Mean age was 62.8 years (SD 10.4). Patients were 84.4% male with 87.4% White, 10.6% Black, 1.8% Hispanic, and 0.3% Asian. Histologically, 86.4% of patients had adenocarcinoma while 11.4% had squamous cell carcinoma. Anastomotic leak occurred in 8.1%, pneumonia in 16.7%, ventilation greater than 48 hours in 20.7%, and discharge to home in 82.1% of patients. 30-day readmission occurred in 16.4% and 90-day mortality in 6.1% of patients. 8 patients did not have CT scans available. Analysis of 90-day mortality as a function of age >75 and SMG risk group showed 33.3% mortality among patients >75 in Q1 for SMG, 9.6% for patients <75 in Q1 for SMG, 5.6% for patients >75 in Q234 for SMG, and 2.2% in 264 patients <75 in Q234 for SMG for subjects who had available scan data (n = 388). Conclusions: As expected, patients with older age and lower SMG have higher mortality after esophagectomy compared to younger patients with higher SMG. Patients who are >75 years old and in the bottom SMG quartile represent a small group (27/388 = 7% of the total) which are identified as a high-risk group with a mortality of 33.3%. This study identifies a small subset of patients whose risk of surgery may outweigh the benefit, particularly in patients already treated with chemoradiation. Preoperative body composition, as measured by SMG, in combination with age can be used to predict postoperative mortality after minimally invasive esophagectomy and guide treatment decisions.