Diabetes mellitus is one of the most frequent chronic diseases of the elderly population with a high prevalence after the age of 65 years. In this group it is a serious cause of increased mortality and morbidity. More than 90% of patients suffer from type 2 diabetes mellitus. The disease takes frequently for a long time an asymptomatic course and if it persists for long it may lead to microvascular complications and is an important risk factor of cardiovascular and cerebrovascular diseases. The objective of treatment of diabetes in old age is in particular to restrict symptomatic hyperglycaemia, but at the same time we must not forget prevention of hypoglycaemia. It is also important to diagnose and treat diabetic complications. As elderly diabetic patients are usually polymorbid, diabetes mellitus in old age calls for a comprehensive approach not only to the treatment of hyperglycaemia but also of hypertension, dyslipidaemia and other associated diseases.