A radiation-free, non-myeloablative, myelosuppressive protocol, containing dibromomannitol and cytosine arabinoside, that remarkably reduced the frequency of transplant-related complications, such as veno-occlusive liver disease (VOLD), severe mucositis, bacterial sepsis, hemorrhagic cystitis, interstitial pneumonitis, has been applied in 19 CML patients, allotransplanted from identical siblings. Five patients were in accelerated phase. Acute GVHD developed in two patients and chronic GVHD occurred in 66% of patients. Follow-up was 3 to 7 1/2 years. Although only eight patients were under 30 years of age, and only two patients had a history of less than 1 year, the leukemia-free survival was 82%. There were four hematological relapses. The reduction in post-BMT complications has greatly enhanced quality of life. The nurses reported significant reduction of work-load. Savings in eliminating the need for irradiation, parenteral nutrition, and several antibiotics are also remarkable. The remarkable reduction of certain transplant-related complications shows some advantage against busulphan-preconditioning.