19 children with AML were treated using the combination of high dose cytosine-arabinoside and mitoxantrone. All children were initially treated according to protocol AML-BFM-83. 6 children with refractory AML, 9 children with bone-marrow relapse during or after maintenance therapy and 4 children with residual blasts (5-25%) after remission induction and consolidation therapy AML-BFM 83 were treated with the relapse protocol. 6 of 15 children with refractory AML and all 4 children with residual blasts achieved a complete remission. 2 children died in bone-marrow aplasia and 1 child did not respond. One child died after further mitoxantrone treatment due to toxic cardiomyopathy. All children went into severe bone marrow aplasia, which lasted in median 27 days. These data indicate a high antileukemic activity of HD-ARA C/mitoxantrone in childhood AML.