Despite the abundance of reports describing adult cases of t(8;21) acute myelocytic leukemia (AML), childhood cases have received little attention. We retrospectively investigated 14 childhood cases of t(8;21) AML, and compared their clinical characteristics with those of adult cases, focusing on the risk factors for poor prognosis. Seventy-one percent of the patients had fever. Their mean leukocyte count was 12,700/microliter, and they showed decreased NAP activity. The cell surface showed positivity for CD13, 33, 19, 34, and HLA-DR. The complete remission rate was 100%, and relapse was observed in three of the patients. Bone marrow eosinophilia was present in a smaller proportion of the childhood cases than in the adult cases. Although an increased leukocyte count, tumor formation, and other risk factors have been reported in adults, there was no correlation between these factors and prognosis in our childhood cases. As children who showed AML relapse had TdT-positive blasts, detectable blast TdT activity may be a risk factor for relapse in childhood cases of t(8;21) AML. However, to confirm this, a study with a larger subject base should be conducted.