Diabetes mellitus is a metabolic disorder caused by an absolute or relative lack of insulin. It used to be considered as a disease of minor epidemiological importance. Now it is considered as one of the main causes of premature mortality. Type 2 diabetes mellitus patients represent 85-95% of all diabetic cases. Rapid diagnosis of this illness makes any complications less likely to happen. The basis for selecting the drug is an individual assessment of patophysiological and clinical features of type 2 diabetic cases. The oral antidiabetic drugs and diet are the major agents used in the management of this illness. New generations of antidiabetic drugs are characterized by a wide range pharmacological activity. They are also safer then the old ones. At present following groups of drugs can be used in the treatment of type 2 diabetes: sulphonylureas, biguanide derivatives, glinides, α-glucosidase inhibitors, thiazolidinediones, incretine drugs and insulin.