We have evaluated the activity and toxicity of cytosine arabinoside (ara-C; 750 mg/m2 intravenously given over 3 hours every 12 hours for 12 doses) to induce remission in older (median age, 73 years) newly diagnosed patients who had acute myelogenous leukemia (AML). A maximum of two cycles of induction were administered. Patients who achieved complete remission could receive three additional consolidation courses limited to 4 to 6 doses of ara-C every 12 hours, depending on marrow cellularity. Thirty patients were evaluable. Twenty-two patients had one or more unfavorable prognostic factors, including antecedent hematologic disorders (10), cytogenetic abnormalities (17), or hyperleucocytosis (5). Fourteen patients (47%) achieved complete remission. Four patients did not receive consolidation as planned because of medical contraindication or refusal, and three patients relapsed during consolidation. The median duration of complete remission was 326 days. Sixteen patients failed induction because of relative or absolute drug resistance in nine patients, or death in seven patients. Median survival for the entire group was 6 months. Toxicity was significant, with a median initial hospitalization of 29 days. These results are comparable to those reported in the literature and suggest that this regimen may be considered to be an alternative to an anthracycline-containing regimen.