We examined retrospectively 44 patients with refractory acute leukemia (acute myeloid leukemia (AML)/acute lymphoblastic leukemia=25/19) who underwent allogeneic transplantation at our center between 11/1990 and 04/2004. The median leukemic blasts was 25% and age 28 years (range, 3-56). Twenty-one patients had untreated relapse, 13 failed reinduction, eight in partial remission and two aplastic. Conditioning was myeloablative using cyclophosphamide, busulfan, total-body irradiation and etoposide (Bu/Cy/VP, n=22; TBI/Cy/VP, n=17; others, n=5) followed by marrow or peripheral blood transplant (n=23/21) from unrelated or related donors (n=28/16). All patients had graft-versus-host disease (GVHD) prophylaxis with cyclosporin and methotrexate. One patient experienced late graft failure. Severe acute-GVHD and chronic-GVHD appeared in eight and 14 patients, respectively. Thirteen patients (30%) remain alive after a median of 25.3 months (range, 2.4-134.1); with 31 deaths, mostly from relapse (n=15) and infections (n=12). Overall survival (OS) and progression-free survival (PFS) at 5 years was 28 and 26%, respectively. OS and PFS were significantly better with blasts < or =20% and time to transplant < or =1 year while transplant-related mortality was less with the use of TBI. We conclude that patients with refractory leukemia can benefit from allogeneic BMT, especially with < or =20% marrow blast.