We report on seven chronic myelogenous leukemia (CML) patients who received autologous bone marrow transplantation (ABMT) using bone marrow (BM) cells while at the chronic phase (CP) under the various treatments. Of the seven patients, four progressed to accelerated phase (AP) in 83-248 weeks after onset and three patients entered blastic crisis (BC) in 84-171 weeks after onset. All patients received high-dose chemoradiotherapy followed by infusion with 11.3 +/- 12.1 x 10(7) (average +/- S.D.) of bone marrow mononuclear cells (BM-MNCs)/kg IFN-alpha was resumed shortly after platelet recovery. Of the four patients in AP, one developed a recurrence of blastoma in 7 weeks, one progressed to second AP in 138 weeks after ABMT and two patients have survived the second CP for 159 and 330 weeks since ABMT, respectively. One of them achieved the complete disappearance of Ph1-positive metaphases for 33 weeks after ABMT. Of patients who received AMBT in BC, three relapsed within 8 weeks and died in 9, 17 and 58 weeks after ABMT, respectively. Hematological recovery was delayed in four patients. Therefore, we retrospectively re-evaluated the number of BM-MNCs collected through 50 procedures from 40 patients with CML-CP. The total MNCs obtained from 30 collections under IFN-alpha treatment was 27.4 +/- 30.9 x 10(8) cells (average +/- S.D.), being significantly lower than that obtained from 20 collections in pre-treatment state or with single chemotherapy other than IFN-alpha treatment (81.8 +/- 68.2 x 10(8) cells) (P < 0.005). The total number of MNCs correlated to white blood cell (WBC) count at BM collection (P < 0.01), which was also lower in the IFN-alpha(+) group than in the IFN-alpha(-) group (7.2 +/- 5.7 and 25.6 +/- 32.3 x 10(9)/l; P < 0.005). Our findings suggested that ABMT with the use of a sufficient number of progenitor cells might be helpful to CML patients in early AP and reach in extended periods of second CP. In addition, we suggest that BM collection is required before the start of IFN-alpha therapy because the total number of BM-MNCs correlated to the WBC count, which might be lower in IFN-alpha treatment.