A sequential study was carried out involving 40 adults with acute nonlymphocytic leukemia (ANLL). The first 20 patients were treated with cytarabine (Ara-C) and 6-thioguanine (6-TG), the second 20 with a regimen that added a three-day course of daunomycin (DNM) to the Ara-C and 6-TG therapy. With both groups well matched for age, patients in the DNM-treated group had a higher complete remission (CR) rate but failed to survive longer than those in the Ara-C and 6-TG treatment group. In a comprehensive literature review of various treatments for adult ANLL, a higher CR rate but not significantly better survival for patients initially treated with DNM-combined regimens was found. Our analysis of cases and literature review suggest that while DNM is a very active drug, its use in the initial treatment of adult ANLL has not produced a significant improvement in overall survival or in survival of those brought into complete remission.