From April 1981 to February 2000, 105 patients with chronic myeloid leukemia (CML) underwent BMT from HLA-identical related donors at a single center. Eighty-eight patients were in chronic phase (CP), 11 patients in accelerated phase and six patients in blast crisis. Ten of these patients received a second BMT (BMT2). Comparison of BMT in CP with chemotherapy and/or alpha-IFN (n=70) was also made. Patients were given cyclophosphamide (CY) and single-dose TBI (CYTBI, n=38) or busulfan (BU) and CY (BUCY, n=67). Overall 54 patients are alive and 52 of them are disease-free with a median follow-up of 11.3 (range 1.1-19.4) years. Ten-year disease-free survival (DFS) in CP patients was better after BUCY, 61% (95% CI, 47-68%) than after CYTBI, 41% (95% CI, 23-61%) (P=0.07). For 88 patients who received a transplant in CP, results were significantly improved when BMT was performed within 1 year after diagnosis (P=0.02) or at an age < or = 25 years old (P=0.01). Ten-year survival in patients who received BMT in CP was better than in patients treated with chemotherapy (56% vs 10%; P=0.0001) or alpha-IFN-based treatment (33%; P=0.09) with survival curves crossing at 4.2 years and at 4 years, respectively. The probability of DFS after BMT2 was 60% (95% CI, 26-87%). CP patients who received BMT after CYTBI had a higher probability of relapse and transplant-related mortality than patients receiving BUCY (53% and 58% vs 9% and 34%; P=0.002 and P=0.08, respectively). All but six patients are currently on no medication and have resumed all activities without any limitation. These long-term results confirm that allogeneic BMT is the only curative approach for CML patients and should be offered to all patients with a suitable donor as soon after diagnosis as possible.