Obesity represents a growing epidemic in the United States. As the population ages and prevalence of obesity increases, the number of obese people admitted to the medical intensive care unit (MICU) will likely increase. Morbid obesity has important physiologic and pathophysiologic effects on organ function, particularly the pulmonary, cardiac, and renal systems. Management of critical illness in the morbidly obese offers many challenges. A brief case presentation highlights some of these difficulties. It remains controversial if morbid obesity increases or decreases mortality among critically ill patients.