Epidemiologic information about specific types of leukemia in Japan is limited because limited data is available from population-based cancer registry. In this review, 1) history of International Classification of Diseases (ICD) about hematological malignancies, 2) current situation of population-based cancer registry for hematological malignancies, and 3) estimated incidence of acute myeloid leukemia (AML) and chronic myeloid leukemia (CML) from selected population-based cancer registries (1993-2002 data from 15 registries) are presented. Estimated incidence of AML and CML in male and female in Japan are approximately half of those from SEER data in the United State. No clear change in incidence of AML/CML was observed between 1993 and 2002.