The present multi-center non-randomized open prospective phase IV study was carried out based at 8 clinical centers of the Russian Federation. It included 89 patients at the age from 6 to 17 years suffering from type 1 diabetes mellitus during a period over 1 year. The children treated with Lantus (insulin glargin) in combination with any short-acting insulin in accordance with the basal-bolus regime and having the HbA1c level from=>8% to =<10% were transferred to Apidra (insulin glulisine) therapy in combination with Lantus insulin. The number of patients in the first age group (6-12 years) having the HbA1c level <8% within 12 months after the onset of therapy was 51.1%. However, only 31.1% of them, did not experience episodes of symptomatic hypoglycemia during this period with the blood glucose level =< 3.1 mmol/l. In the age group 2 (13-17 years), 31.1% of the patients reached the target HbA1c level <7.5% during the 12 month treatment period, but only 13.3% had no episodes of symptomatic hypoglycemia of =<3.1 mmol/l during this period. The HbA1c level in groups 1 and 2 decreased from 8.75±0.6 to 8.05 ±1.06% (p=0.046658) and from 8.77±0.58 to 7.96±1.12% (p=0.017533) respectively. The requirements for insulin in either group did not significantly change throughout the study period. A total of 1866 hypoglycemic episodes were recorded (i.e. 20.73 episodes per patient) including 90.8% of daytime and 9.2% of nocturnal hypoglycemia; symptomatic hypoglycemia accounted for 98.8% of all the cases and asymptomatic one for 1.2%. Fifty three (0.35%) cases were interpreted as severe hypoglycemia (blood glucose level 2 mmol/l), five (0.27%) patients had to be hospitalized . Hypoglycemic episodes were not documented in 13 children.