Recent studies have identified recurrent mutations in genes that encode proteins crucial in the epigenetic regulation of gene transcription in hematologic malignancies. Somatic mutations in epigenetic modifiers, including IDH1, IDH2, TET2, DNAMT3A, ASXL1, MLL and EZH2 are enriched in patients with acute myeloid leukemia (AML), especially those with intermediate-risk cytogenetics. Here we describe the clinic-biologic features of AML patients with these mutations, their prognostic relevance and potential as therapeutic targets. The epigenetic alterations are present as the early pre-leukemic events and usually remain stable during disease evolution, implying the potential to be biomarkers for minimal residual disease monitoring. The high frequency of mutations in epigenetic modifiers and their prognostic implications shed light on the development of epigenetic therapy.