Telomerase is activated in chronic myeloid leukemia (CML); however, it is not known whether the catalytic telomerase reverse transcriptase subunit (hTERT) is vital in the progression of this disease. This study involved patients with CML in the chronic phase (pretreatment and after treatment), accelerated and blastic phase. Expression of the hTERT gene differed significantly among the four major groups (p < 0.05). We also compared hTERT expression according to demographic parameter such as age and sex, and found no significant differences (p > 0.05). Taken together, our findings suggest the importance of hTERT as a valuable molecular marker in the follow-up of patients with CML, which may have clinical implications for the prognosis.