Application of the immunophenotype by flow cytometry to confirm the diagnosis acute myeloid leukemia with minimal differentiation (M0) at Blood Transfusion and Hematology Hospital of Vietnam from Oct., 4th 2012 to March 7th 2013. The study was conducted on case series, analysis of immunophenotype of patients with AML by mono clonal fluoresent antibodies on BD FACSCanto II system. The AML-M0 that are often misdiagnosed as ALL by morphology. Thus, in this case flow cytometry is important to confirm the diagnosis of acute myeloid leukemia with minimal diferentiation (M0).