Abstract Background Already for decades, controversy exists as to whether immunophenotyping has a prognostic significance in acute myeloid leukemia (AML). However, the impact of the immunophenotypic assessment of blast maturity is largely unknown. Objectives Studying the influence of the degree of immunophenotypic maturity, via the application of the flow-cytometric based maturity score, on the clinical outcome as well as the laboratory and clinical parameters of patients with AML. Methods This study was conducted on 40 newly diagnosed AML patients with the quantifications of the variable expressions of three early myeloid progenitor markers namely CD34, CD117 and TdT. After that, the estimation of the blast maturity was based on a previous score proposed in a study by Schneider et al. (2015). Results Out of forty patients enrolled, 8 patients (20%) were assigned to the mature group whereas 32 patients were assigned to the immature group. There was no statistically significant difference between both groups in terms of demographics, clinical and laboratory data, cytogenetic risk groups as well as treatment outcome determined by mortality and response to chemotherapy on day 28 and at 6 months. Mature group showed slightly higher median survival in comparison to the immature group. Conclusion There is no evident relationship between maturity score of the blast population of a patient and the clinical outcome despite mild prolongation of median survival of the mature group. Higher sample size is needed to confirm this observation.