Seven patients with acute myeloid leukemia (AML) in first complete remission were treated with escalating high doses of cyclophosphamide, etoposide, and cytosine arabinoside (Ara-C). In all patients autologous bone marrow preservation was performed prior to therapy. Bone marrow was stored in blood bags in a refrigerator for 48-72 h at 4 degrees C and then reinfused over a central line. All patients had a full hematological recovery. The mean time of neutropenia (neutrophils less than 500/microliters) was 14 days (range 9-24 days), and the mean time of thrombocytopenia (platelets less than 20,000/microliters) was 9 days (range 7-11 days). The nonhematological toxicity was tolerable with mild to moderate nausea/vomiting, mucositis and diarrhea, and so far not dose-limiting. Six patients remain in complete remission 17+, 9+, 5+, 5+, 4+, and 1+ months after autotransplantation. One patient relapsed 8 months after autotransplantation. High-dose chemotherapy with noncryopreserved bone marrow autotransplantation may be useful as intensified consolidation for patients with AML in first complete remission.