Background DNA methylation is involved in pathogenesis of acute myeloid leukemia (AML). N6-methyladenosine (m6A) modification of mRNA, mediated by methyltransferase-like 3 (METTL3), is one of the well-identified mRNA modifiers associated with the pathogenesis of AML. High level of METTL3 mRNA is detected in AML cells, thus can be a potential target therapy for AML. This is a preliminary study that aimed at measuring METTL3 mRNA expression level in de novo AML patients and correlating it with clinicopathological, laboratory and prognostic markers. METTL3 expression was analyzed by quantitative reverse transcription polymerase chain reaction in 40 newly diagnosed AML adults and was re-measured in the 2nd month of chemotherapy. Patients were followed up for periods up to 6 months post-induction therapy. Results METTL3 expression was found to be significantly upregulated in AML patients compared to control subjects (p < 0.001). METTL3 gene was significantly expressed among non-responders compared to responders (p < 0.001). A cutoff value was assigned for normalized METTL3 values to categorize AML patients according to response to therapy. Statistically significant association was observed between high pretreatment normalized METTL3 gene level and failure to attain complete remission at 2nd, 4th and 6th month following therapy (p = 0.01, 0.02 and 0.003, respectively). However, insignificant correlation was found between pretreatment normalized METTL3 gene level and event free survival or clinicopathological prognostic factors. Conclusion METTL3 is overexpressed in AML patients and is associated with adverse prognostic effect and failure to attain hematological remission within 6 months post-induction therapy.