Idarubicin (IDR) is a new anthracycline that can be administered orally. Oral IDR was given at a dose of 30 mg/m2 daily for 3 d in 20 patients aged 65 to 79 yr with previously untreated acute myeloid leukemia (AML). 5 patients whose marrow remained blastic at d 14 received a second course. 8 patients achieved complete remission (6 after one single course). There were: 1 early death, 4 deaths in aplasia, 7 failures. The hematologic toxicity was high. All but 1 patient had to stay in hospital and the duration of neutropenia was 12 to 34 d (median 19). Oral IDR is an effective therapy for AML in elderly patients but the total dose of 90 mg/m2 is too aggressive to be administered safely outside the hospital.