Chronic myeloid leukemia (CML) is a myeloproliferative malignancy due to the formation of the BCR-ABL fusion gene in chronic myeloid leukemia. This condition causes excessive cell proliferation, resulting in an increase in the number of leukocytes. Tyrosine Kinase Inhibitor (TKI) is a first-line therapy that helps reduce  the percentage of the BCR-ABL fusion gene in patients with chronic myeloid leukemia. This study was conducted to determine differences in the hematological profiles (hemoglobin levels, leukocyte counts, platelet counts) and molecular BCR-ABL in patients with chronic myeloid leukemia before and after 12 months of tyrosine kinase inhibitors therapy. This analytic observational study was administered using a cross-sectional design to in analyzing the medical records of CML patients who underwent TKI therapy at the Sub Specialist Polyclinic of Internal Medicine Hematology Oncology Ulin Banjarmasin Regional Hospital from March 2021-April 2022. Dependent T-test and McNemar's test were performed in data analysis which results showed that 12 month tyrosine kinase inhibitor therapy could increase the hemoglobin levels, decrease leukocyte counts, platelet counts as well as decreasing the percentage of BCR-ABL gene fusion in patients with chronic myeloid leukemia. In conclusion, significant differences were found in the hematological profiles (p<0.001) and the molecular BCR-ABL (p<0.001) before and after 12 months of tyrosine kinase inhibitor therapy