Twenty-two newly diagnosed adults with acute non-lymphocytic leukemia (ANLL) and 18 who had relapsed from a prior complete remission (CR) obtained with intensive chemotherapy were treated with a combination of Adriamycin, cytosine arabinoside, 6-thioguanine, prednisone, and vincristine. Eighteen (82%) of the patients undergoing initial induction therapy, including 4 of 6 patients over 60 years of age, achieved CR. Twelve patients (67%) undergoing reinduction therapy also achieved CR. Twenty-three (77%) of the 30 CRs were obtained with only one course of chemotherapy. The median time to CR for those undergoing initial treatment was 32 days, and the median duration of CR is 10+ months. The median survival for all 22 newly diagnosed patients is 15+ months. This intensive five-drug regimen is highly effective for the remission induction of both newly diagnosed and previously treated patients with ANLL producing a high percentage of CRs with only one course of therapy.