Mitoxantrone in combination with VP-16 proved to be effective in refractory and relapsed acute myeloid leukemia (AML), with 42% of patients achieving complete remission (CR). The aim of this study was to assess whether the addition of cytosine arabinoside increased the response rate at a tolerable toxicity. The regimen consisted of mitoxantrone (M) 10 mg/m2 i.v. days 4-8, cytosine arabinoside (A) 100 mg/m2 continuous infusion days 1-8, and etoposide (VP-16) (V) 100-120 mg/m2 i.v. days 4-8 (MAV protocol) for relapsed and refractory AML. Thirty-six patients were treated, with a median age of 51 (20-73) years. For induction therapy one to two MAV cycles and for consolidation therapy two courses were scheduled. Twenty-one (58.3%) patients attained a complete remission (CR), with a median duration of 4.5 (1-12+) months. The median survival of all patients was 5.5 (0.5-15.5+) months. Four patients died in CR from chronic infections or after consolidation therapy with MAV. In evaluable patients, times to greater than 500 granulocytes/microliters and greater than 25,000 platelets/microliters were 23 (7-46) and 23 (6-44) days, respectively. In 54 evaluable MAV courses the following toxicity was observed (WHO grades 3/4): 26%, nausea and vomiting: 9%, hemorrhage; 6%, bilirubinemia; 11%, diarrhea; 22%, mucositis; 6%, local infection; 20%, septicemia; 13%, fever of unknown origin; 2%, cardiac arrhythmia; 7%, congestive heart failure. We conclude that MAV therapy is a highly active antileukemic combination with acceptable toxicity, which is recommended for further clinical trials in untreated AML.