Idarubicin (IDR) has been used as the main drug in induction chemotherapy for acute myelogenous leukemia (AML) in the USA and Europe. Between May 1995 and October 1998, we treated 41 cases of fresh AML using IDR induction chemotherapy and analyzed the clinical course, remission rate, relapse rate and prognosis. The results obtained in these cases were similar to those in 26 cases treated with daunorubicin (DNR) in our hospital according to JALSG-AML92. The outcome in cases with abnormal chromosomes and cases showing relapse was very poor. In particular, all 5 t(8;21) cases in our series relapsed, suggesting that t(8;21) cannot be considered a favorable prognostic factor in cases treated with IDR-containing regimens. However, 3 of the 5 t(8;21) cases were positive for CD56, which itself is an unfavorable prognostic factor. Thus it is possible that CD56 was related to the poor outcome. Intensive post-remission induction chemotherapies will be required in order to obtain prolonged disease-free survival.