We studied fifteen patients older than 80 years of age with acute myelogenous leukemia (AML) treated between 1984 and 1996. Among 15 cases of AML including 7 de novo cases and 8 from myelodysplastic syndrome (MDS) or hypoplastic leukemia, 14 patients had complications, including cardiovascular disease, diabetes mellitus or other malignancies. Although patients with de novo AML showed high peripheral WBC counts and higher cellularity of bone marrow than those from MDS or hypoplastic leukemia, it was difficult in some cases to distinguish these types of AML from hematological findings. Of the 6 AML cases, three had entered complete remission (CR) by a standard dose of combination chemotherapy (BHAC-DMP). One CR patient has had CR for more than 9 years now with good QOL. Among the 3 patients treated by low-dose Ara-C, one attained CR but only for a short period. Four other patients received BRM, such as G-CSF or Ubenimex, and 2 patients died without chemotherapy. Since AML at more than 80 years of age is a highly heterogenous disease, it would be reasonable to give antileukemic agents according to the individual patient's condition.