A patient, who was treated twice with donor lymphocyte infusions for relapse of CML after an allogeneic BMT was given lymphoblastoid human alpha-IFN after a third relapse. Further donor lymphocyte infusions were followed by repeated courses of 30 days treatment with a low dosage of IL-2 subcutaneously, alternately with alpha-IFN. This treatment resulted in a hematologic and cytogenetic remission. He also developed a limited degree of chronic GVHD. At the latest follow-up at 20 months after the third course of lymphocyte infusions he is in continuous hematologic and cytogenetic remission. Furthermore, a qualitative PCR analysis for the bcr/abl translocation is negative.