A 28-year-old man who had received an allogeneic bone marrow transplant 7 years earlier experienced a relapse of chronic myelogenous leukemia in an accelerated phase. He was unsuccessfully treated with vincristine (VCR) and interferon-alpha (IFN-alpha), and subsequently received a donor leukocyte transfusion (CD3+ cells: 1.5 x 10(7)/kg). Rapid hematologic recovery was observed and a complete remission was obtained without graft-versus-host disease (GVHD) or bone marrow aplasia. It may be that the preceding regimen of chemotherapy (VCR + IFN-alpha) contributed to the patient's recovery by reducing the tumor burden.