Bone marrow transplantation is the only therapy currently available with the potential to cure chronic myelogenous leukemia. The best results and most experience have been in HLA-matched transplants for patients with CML in the chronic phase. Various protocols have resulted in lengthy disease-free survival in 49-69% of patients. The limitation to greater success is significant mortality associated with graft-versus-host disease. Attempts to improve results have focused on decreasing GVHD by drug regimens or removing donor T-cells. Studies using T-cell depletion by different techniques have improved survival in groups with higher median patient age. These methods have had varying effects on incidence of GVHD, graft failure, and relapse. Transplant for patients in the advanced phases of CML have produced lower disease-free survival rates, due mainly to resistant disease. Early experience with busulfan and cyclophosphamide conditioning have shown improved survival in these patients.