Our pilot study addresses the problem of early relapse from complete remission in young adults with acute myelogenous leukemia (AML). Twelve patients with AML, 16-58 years of age, were entered in a study of four intense courses of cytotoxic chemotherapy using the following drugs: cytarabine, daunorubicin, 5-azacitidine, and 6-thioguanine. They received no maintenance therapy. Nine of 12 patients achieved complete response. With a minimum follow-up of 35 months, the observed disease-free survival at 2 years was 67% (14 +/- SE) and the actuarial disease-free survival at 4 years was 38% (17 +/- SE). It appears that brief intensive chemotherapy early in the management of AML can produce prolonged remission without the need for maintenance therapy.