Data on 281 patients with chronic myelogenous leukemia who received bone marrow transplants were analyzed. The median follow-up time was 48 months. One hundred and seventy patients were in 1st chronic phase, 111 were in more advanced disease. The overall actuarial survival was 50% at 5 years. In multivariate analyses, the probability of relapse was 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 GVHD. The probability of disease free survival was significantly better for the patients who received a non T cell depleted marrow than for recipients of T cell depleted marrow. Bone marrow transplantion in first chronic phase with an HLA identical non T cell depleted marrow offers the better chance of prolonged leukemia free survival.