Fourteen patients with poor-risk acute myelogenous leukaemia (AML) and five patients with accelerated phase/blast crisis chronic myeloid leukaemia (CML) were treated with 3 days of oral idarubicin (25 mg/m2/day). No complete remissions or return to chronic phase CML were observed. A fall in the peripheral blast count was seen in all patients with the first cycle of treatment, and with subsequent cycles in CML patients, but all responses were transient, with eventual reemergence of peripheral blasts. In some patients, there was a clear cut improvement in symptoms such as bone and splenic pain. Five of the AML patients and all of the CML patients were treated as out-patients. In this group of patients oral idarubicin was found to be a useful drug for palliative treatment.