Between July 1987 and December 1992, we treated 22 patients with chronic myelogenous leukemia; 14 in the chronic phase and 8 with more advanced disease. All were received with allogeneic bone marrow transplantation from HLA-identical sibling donors after a total body irradiation(TBI) cyclophosphamide conditioning regimen. Patients were non-randomly assigned to either 1200 cGy/6fractions/3days (6 patients) or 1320 cGy/8 fractions/4days (16 patients) by dose of TBI. Of the 22 patients, 8 were prepared with cyclophosphamide alone, 14 were conditioned with additional adriamycin or daunorubicin. To prevent graft versus host disease, cyclosporine was given either alone or in conjunction with methotrexate. The actuarial survival and leukemic-free survival at four years were $58.5\%$ and $41.2\%$, respectively, and the relapse rate was $36\%$ among 22 patients. There was a statistically significant difference in survival between the patients in chronic phase and more advanced phase ($76\%;vs;33\%$, p=0.05). The relapse rate of patients receiving splenectomy was higher than that of patients receiving splenic irradiation ($50\%;vs;0\%$, p=0.04). We conclude that the probability of cure is highest if transplantation is performed while the patients remains in the chronic phase.