Data on 281 patients with chronic myelogenous leukemia who received bone marrow transplants were analysed. The median follow-up time was 40 months; 170 patients were in first chronic phase, 14 were in second chronic phase, 73 were in accelerated phase and 24 were in blastic crisis. The overall actuarial survival was 50% at 5 years. In multivariate analyses, the probability of relapse correlated with the phase of the disease, the method of total body irradiation, the T cell depletion of the marrow and the occurrence of a chronic graft-versus-host disease (GVHD). The probability of survival was better for patients with grade 0-1 GVHD than for patients with grade 2-4 GVHD. In contrast, the probability of disease-free survival was significantly better for patients who received a non-T cell-depleted marrow than for recipients of T cell-depleted marrow. Interval between diagnosis and transplant, splenectomy before transplant, patient age and donor recipient sex match were not significantly associated with outcome. Bone marrow transplantation in first chronic phase with an HLA identical non-T cell depleted marrow offers the better chance of prolonged leukemia-free survival.