Introduction: Hyperglycemia and insulin resistance are common in critically ill patients, even if they have not previously had diabetes, and the risk of mortality or significant morbidity is high among those who are treated in the intensive care unit (ICU) for more than 5 days. Objective: To assess the effect of glucose management protocol on mortality and morbidity in a heterogeneous population of critically ill adult patients. Design: A randomized controlled trial. Setting: A 24-bed medical-surgical intensive care unit (ICU) for adult patients at King Hussein Medical Center, the Royal Medical Services. Methods: A total of 50 patients who were considered to need intensive care for at least three days, were randomly assigned into two groups. The intervention group subjects were to undergo a glucose control protocol with insulin infusion titrated to maintain blood glucose level in a target range of 120-160 mg/dL; except septic patients, in whom the target was higher, 160-180 mg/dL. Patients in the second group (control group) were treated by a