Imatinib (IM) treatment efficacy in 116 chronic myeloid leukemia (CML) patients in different studies was analyzed. Patient group was non‑selective with prospective enrollment. The study was based on real‑time patient’s register allows to treatment quality control due to clinical results. Cytogenetic response (CO), hematological data, and overall survival (OS) were used as criteria for the therapy efficacy. After 12 month of treatment in 46.4 % of CML patients in early chronic phase complete CO (CCO) was obtained, in 33.3 % — in the late chronic phase, and in 13.3 % — in accelerated phase. Deficit of daily imatinib dose and intervals in treatment schedule were made a negative influence on CO quality. The median of OS was 120 months.