We report the case of a 44-year-old male who relapsed in accelerated phase chronic myeloid leukemia 10 years after a successful bone marrow transplantation from his HLA-identical brother, and 3 years after 12 months treatment with interferon-alpha (IFN-alpha) for chronic active hepatitis C (CAH). The patient was infused with G-CSF-primed peripheral blood cells (PBSC) from the original bone marrow donor and a full donor reconstitution, with no detectable molecular disease, was obtained within 4 months without clinical aplasia or GVHD, nor help from other forms of chemotherapy or use of biological response modifiers. We speculate that IFN-alpha for CAH delayed the onset of a clinical recurrence of chronic myeloid leukemia and that in advanced disease PBSCs can provide an advantageous alternative to donor lymphocyte infusion (DLI).