Diabetes mellitus is prevalent among the elderly. Although the principles of management of diabetes are fundamentally the same in both the young and elderly, many aspects of the disease and its manifestations are unique to the elderly. Older patients may have atypical presentations of diabetes. Numerous factors may impair adequate nutrition and dietary and exercise compliance in the elderly. Pharmacologic therapy, with either sulfonylureas or insulin, entails a particular risk for hypoglycemia among the elderly, who are more susceptible to hypoglycemia and are more likely to have neuroglycopenic symptoms. Diabetic hyperosmolar coma occurs predominantly in the older type II diabetic population. It requires aggressive hydration and insulin therapy, but most patients can ultimately be managed without insulin. The macrovascular complications (coronary and peripheral vascular disease) are the major source of morbidity and mortality among elderly diabetics, but microvascular complications (nephropathy, retinopathy, neuropathy) also occur and often respond to a variety of therapeutic interventions.