Previous study has revealed that H19 expression is required for efficient tumor growth induced by BCR‐ABL in chronic myeloid leukemia (CML). Herein, we further determined H19 expression and its clinical implication in patients with CML. H19 expression and methylation were detected by real‐time quantitative PCR and real‐time quantitative methylation‐specific PCR, and then clinical implication of H19 expression was further analyzed. H19 expression was significantly up‐regulated in CML patients (p < 0.001). H19 expression with an area under receiver operating characteristic curve value of 0.824 might serve as a promising biomarker in distinguishing CML patients from controls. The patients with high H19 expression had a tendency of higher white blood cells and BCR‐ABL transcript than those with low H19 expression. H19 overexpression occurred with the higher frequency in blast crisis stage (11/11, 100%), lower in accelerated phase (3/5, 60%), and chronic phase (42/62, 66%) stages. Moreover, paired patients during disease progression with increased BCR‐ABL transcript also showed a significant upregulation of H19 expression. Meanwhile, H19 expression was decreased in follow‐up patients who achieved complete molecular remission after tyrosine kinase inhibitors‐based therapy. Epigenetic studies showed that H19 differentially methylated region/imprinting control region (DMR/ICR) was hypomethylated and associated with H19 expression in CML patients. Moreover, demethylation of H19 DMR/ICR reactivated H19 expression in K562 cells. Collectively, H19 overexpression, a frequent event in CML, was associated with higher BCR‐ABL transcript involving in disease progression. Moreover, H19 DMR/ICR hypomethylation in CML may be one of the mechanisms mediating H19 overexpression. H19 overexpression, a frequent event in CML, was associated with higher BCR‐ABL transcript involving in disease progression. H19 DMR/ICR hypomethylation in CML may be one of the mechanisms mediating H19 overexpression.