Fifty-three patients of median age 66 years (39 patients > 60 yrs), including 5 with FAB unclassified or secondary acute myeloid leukemia (AML) at diagnosis, 14 with resistant AML, 19 in first and 15 in subsequent relapse, were treated with carboplatin (CBP), 200 mg/m2/day, as a continuous infusion, (days 3 to 7) with mitoxantrone (MIT) or idarubicin (IDA), (12 mg/m2/day) as an i.v. bolus, on days 1 to 3. Results were evaluated after one induction course. Overall, 15 patients (28% [95% confidence interval (CI), 17-42%], 8/28 with IDA and 7/25 with MIT) achieved complete remission (CR). There was no statistical difference between IDA and MIT arms. Fourty-nine percent (95% CI, 35-63%) had resistant disease (53% IDA versus 44% MIT respectively) and 23% (95% CI, 12-36%) died from toxicity (18% IDA versus 28% MIT). Median durations of neutrophils less than 0.5 x 10(9)/l and platelet counts less than 20 x 10(9)/l were 32 and 32 days respectively in the IDA arm and 31 and 26 days respectively in the MIT arm. Severe toxicity included infections (45%), diarrhea (21%), bleeding (9%), vomiting (7%), hyperbilirubinemia (6%), mucositis (4%) (no statistical difference was seen between both arms). Nephrotoxicity was observed in only one case in the IDA arm. Cardiac toxicity included reversible pulmonary oedema in one patient in the IDA arm. No severe ototoxicity was noted. CR patients received maintenance courses with 3 days of CBP and one day of IDA or MIT. Median survival was 2 months (range, 1-30+ months) and 2.5 months (range, 0.5-19.5 months), and median disease-free survival (DFS) 2 months (range, 1-30+ months) and 2.5 months (range, 1-14 months) in the IDA and MIT arms respectively. We conclude that CBP at a cumulative dosage of 1 g/m2 together with intercalating agents (IDA/MIT) has antileukemic efficacy in elderly patients.