The prevalence of both type 2 diabetes and prediabetes increases with advancing age. The most important factors leading to hyperglycaemia are as follows: deficiency of insulin secretion developing with age, and growing insulin resistance caused by a change in body composition and sarcopaenia. Clinical features of diabetes in the elderly could be different. Diabetes in elderly people is often diagnosed with delay due to atypical symptoms (dementia, urinary incontinence) and occurrence of mainly postprandial hyperglycaemia. Elderly people are more exposed to diabetes complications, have more risk of myocardial infarction and end-stage renal disease, and are hospitalised more often due to hypoglycaemia than are younger patients. Elderly people with diabetes are a heterogeneous group with different life expectancy, concomitant of chronic diseases, and the ability to self-control blood glucose or give themselves an injection. The therapy should be individualised. Older people with long-term diabetes and numerous chronic complications need a more liberal approach to reach specific goals of therapy. Additional goals should be avoiding hypoglycaemia, safety of the therapy, and its acceptance by the patient.