The feasibility of intensified therapy in adults < 61-years-old with de novo acute myeloid leukemia (AML) was evaluated by adding high-dose cytarabine (HDAC) to conventional induction therapy and in post-remission therapy prior to peripheral blood stem cell transplantation (PBSCT). Patients were treated with conventional induction therapy (daunorubicin days 1-3 and cytarabine days 1-7), followed by HDAC (2 gm/M2) every 12 h ( x 6) on days 8-10. Patients in complete remission (CR) with HLA-matched siblings were assigned to allogeneic PBSCT; the others received two courses of HDAC (3 gm/M2 every 12 h on days 1, 3, and 5) given 1 month apart. Peripheral blood stem cells were then harvested and infused after high-dose chemotherapy. Of 62 eligible, evaluable patients, 47 (76%) achieved CR. The mortality rate was 10% (6 patients); no deaths occurred during the two post-remission courses of HDAC. Fifteen patients were assigned to allogeneic PBSCT and 32 to autologous PBSCT. All surviving patients have been followed for more than 4 years. Including all patients scheduled to receive autoPBSCT in an intent-to-treat analysis, after a median 5-year follow-up the current, non-actuarial, four-year event-free and overall survival was 47% and 47%, respectively. Intensified induction therapy was associated with more toxicity than conventional induction therapy, and the CR rate did not improve. Nevertheless, intensive post-remission therapy was well tolerated, no treatment-related mortality occurred with autologous PBSCT, and disease-free survival and overall survival were lengthy.