Molecular monitoring of BCR-ABL transcript levels by quantitative PCR is increasingly used to assess patient response to treatment. This has become particularly interesting in the imatinib era when residual disease falls below the detection threshold of conventional cytogenetics. The main objective of our work is to study the evolution of CML by quantifying the BCR/ABL molecular transcript during the therapeutic phase. This is a retrospective, descriptive study of 30 patients followed in the hematology department of Tizi Ouzou University Hospital, in the consultation unit. Molecular follow-up showed that 70% of patients achieved MMR with imatinib 400 mg, and 20% of patients who failed imatinib 400 and 600 mg were substituted with a second-generation TKI with 100% MMR. Quantification of the BCR/Abl ratio showed that 96% of patients on imatinib 400mg were cured. In conclusion, optimizing treatment and using the various TKIs available requires biomolecular monitoring of BCR/Abl transcripts right from diagnosis.