Acute megakaryoblastic leukemia (AMKL) in a 9-month old girl and in a 2-year-2-month old boy are reported. Both patients did not have any phenotypes for Down's syndrome and presented with anemia and severe thrombocytopenia. In both cases, blasts were positive for acid phosphatase but negative for myeloperoxidase, naphthol AS-D chloroacetate esterase or α-naphthyl butyrate esterase. A majority of blasts showed positive reaction to KOR-P77 and anti-GPIIb/IIIa monoclonal antibody. The platelet peroxidase reaction (PPO) was mostly negative in one case but positive in another case. Partial remission was obtained after BH-AC/ACM therapy in both cases. In one case, complete remission (CR) was attained by subsequent MTX/VCR/L-asp/Pred therapy.Analysis of 28 pediatric AMKL cases in the literature and our 2 cases demonstrated; Median age was 1.5 year old, Down's syndrome 9/30, PPO negative 4/27, chromsome abnormalities 20/23 (15 with NO. 21/7 with NO. 7 abnormalities) and CR rate 19/28.