||When patients with diabetes are hospitalized, their glucose control may be suboptimal because oral medications are often stopped on admission. 1 In fact, high blood sugar levels, or hyperglycemia, are common among hospitalized patients2 and linked to complications, such as increased morbidity, mortality, and hospital stay. 3 Although low blood sugar levels, or hypoglycemia are serious risks associated with insulin therapy, potentially leading to arrhythmias and other cardiac events,2,4 better glucose control with insulin for both type 1 and type 2 diabetes may improve clinical outcomes and prevent complications in hospitals. 3 Hyperglycemia occurring during hospital stay was traditionally controlled, using sliding-scale insulin therapy, consisting of the administration of regular or rapid-acting insulin approximately five to 30 minutes before meals, based on before-meal measurements of capillary blood glucose. 3,5 Basal-bolus insulin therapy more closely mimics physiological insulin secretion, where pancreatic beta cells release insulin continuously to maintain basal metabolic glucose regulation and extra insulin in response to meals,2 and is recommended today. 3 In basal-bolus insulin therapy, a patient would be given a basal (long-acting) insulin once or twice daily, a nutritional (short- or rapid-acting) insulin before meals, and a correctional (short- or rapid-acting) insulin for any unanticipated before-meal hyperglycemia. 2 Long-acting insulins include detemir and glargine,4,5 and short-acting insulins include aspart and glulisine. 5 There are also intermediate-acting insulins, such as neutral protamine Hagedorn (NPH).4 Despite its inconsistency with physiological insulin secretion, sliding-scale insulin therapy continues to be widely used today because of its simplicity and convenience. 3,5 The purpose of this report is to provide evidence on the clinical benefits and harms and cost-effectiveness of basal-bolus versus sliding-scale insulin therapy for adult patients with type 1 or type 2 diabetes in the acute care hospital setting.