OBJECTIVE: Coronavirus disease 2019 (COVID-19) continues to spread, and younger patients are also being critically affected. This study analyzed obesity as an independent risk factor for mortality in hospitalized patients younger than 50. METHODS: This study retrospectively analyzed data of patients with COVID-19 who were hospitalized to a large academic hospital system in New York City between March 1, 2020, and May 17, 2020. Data included demographics, comorbidities, BMI, and smoking status. Obesity groups included the following: BMI of 30 to < 40 kg/m(2) and BMI >/= 40 kg/m(2) . Multivariable logistic regression models identified variables independently associated with mortality in patients younger and older than 50. RESULTS: Overall, 3,406 patients were included; 572 (17.0%) patients were younger than 50. In the younger age group, 60 (10.5%) patients died. In the older age group, 1,076 (38.0%) patients died. For the younger population, BMI >/= 40 was independently associated with mortality (adjusted odds ratio 5.1; 95% CI: 2.3-11.1). For the older population, BMI >/= 40 was also independently associated with mortality to a lesser extent (adjusted odds ratio 1.6; 95% CI: 1.2-2.3). CONCLUSIONS: This study demonstrates that hospitalized patients younger than 50 with severe obesity are more likely to die of COVID-19. This is particularly relevant in the Western world, where obesity rates are high.