The article considers the urgency of the problem of diabetes mellitus incidence (DM) in the world today. It is emphasized that at the present stage of development of diabetology main goal of DM treatment is to achieve blood glucose levels, as close as possible to the physiological ones, without increasing the risk of hypoglycemia and without harm to the quality of life of patients. Attention is paid to the treatment with emphasis on the fact that priority should be given to drugs with minimal risk of hypoglycemia, and while choosing the combination therapy is is particularly important to consider the use of drugs with mechanisms of action that complement each other. Separately, the reasons of failures in the treatment and in the disease compensations are considered.