Between 1980 and 1996, we transplanted 72 patients with CML using blood stem cells collected at diagnosis before treatment and without any mobilization. The median age of patients at diagnosis was 47.5 years (range 20.5-59.5). The median numbers of nucleated cells and CFU-GM transplanted were 10 x 10(8)/kg and 97 x 10(4)/kg, respectively. The median duration to reach more than 0.5 x 10(9)/l neutrophils and 50 x 10(9)/l platelets was 12 (range 5-19) and 11 days (range 0-79), respectively. Twenty patients (group I) were transplanted in chronic phase either for resistance to IFN (14 patients) (group IA) or because the Sokal index was more than 1.2 (six patients) (group IB). All those patients had preparative regimen with busulfan (4 mg/kg/day x 4) and melphalan (140 mg/m2). They were treated with recombinant alpha-interferon (IFN) after transplant. The cumulative incidence of major cytogenetic response (MCR) at 12 months was 25 +/- 21% (95% CI), the 5-year survival was 75 +/- 42% (95% CI). These results (observed in patients with bad prognosis factors) are similar to those usually observed in CML patients treated by IFN, whatever the Sokal risk. Thus autologous transplantation is able to reproduce for poor prognosis patients the results observed in standard risk patients treated with IFN. This suggests that it could prolong survival. Fifty-two other patients (group II) were transplanted for CML in transformation (accelerated phase = 32; blast crisis = 20) after a preparative regimen containing either total body irradiation (TBI) or busulfan. The median survival was short (10.4 months) and only 21 patients survived more than 1 year. The survival was longer for patients transplanted in accelerated phase (vs blast crisis), those who were due to receive a double transplant (vs single) (34 patients), those who were treated with IFN after transplant (vs hydroxyurea) and for the patients who obtained a complete hematologic response.