Insulin resistance is common and often multifactorial in acutely critically ill patients. At our institution, glycemic control is achieved in these patients using an intravenous insulin protocol. The authors present a case in which a patient developed severe insulin resistance following surgical repair of a thoracic aorta aneurysm. Postoperatively, the patient required 2110 units of insulin over 40 hours while receiving pressors and glucocorticoids. After the administration of intravenous chromium at 3 μg/h, the blood sugar normalized and insulin therapy was discontinued. This case represents a unique approach using intravenous chromium to achieve glycemic control in a patient with extreme insulin resistance and acute critical illness. Prospective clinical trials using intravenous chromium may provide the means to optimize intensive insulin therapy for critically ill patients.