OBJECTIVES: To analyze the effectiveness and safety of 3 treatment regimens, and to project and compare long-term outcomes and costs of complications of type 2 diabetes mellitus (T2DM).  METHODS: Data of 3678  patients  (mean age 49.6±0.19 years; 47% men; mean diabetes’s duration - 6 years) included in “evaluation of diabetes mellitus complications” program were taken for mathematic simulation using the validated Center for Outcomes Research (CORE) Diabetes Model. Patients were randomly divided into 3 groups: insulin therapy (NovoMix® 30), oral antidiabetic drugs (OAD; combination of glibenclamide + metformin in most cases) and diet. Life expectancy, cumulative incidence of cardiovascular, ocular events and healthcare costs were estimated over period duration – 50 years.  RESULTS: Estimated life expectancy was higher in insulin group compared with OAD and diet groups (17.2, 16.5 and 16.0 years). The best QALY’s results were also achieved in insulin group (10.7, 10.2 and 9.9 years) due to decreased rates of myocardial infarction (morbidity/mortality), decompensated heart failure, ocular complications and diabetic retinopathy. Higher direct costs for years of life gained in insulin group (1287, 1203 and 1180 thousands of rub.) were associated with concomitant decreasing of indirect costs (362.7, 382.5 and 381.3 thousands of rub.). The costs for 1 patient with T2DM per 1 year were nearly the same in 3 groups (95.9, 95.9 and 97.6 thousands of rub.).  CONCLUSIONS: use of the CORE Diabetes Model life expectancy, diabetes complications, and costs favored insulin NovoMix® 30 therapies compared with OAD or diet in treatment of T2DM.