Retrospective analysis of 102 children with CML from 9 paediatric centres in Poland has been performed. A total number of 102 children: 58 boys and 44 girls aged 1-17 years (median 9.4 years old) with CML, treated in the period 1975-1999 were included in the study. Forty eight of 102 (47.1 %) children were treated with cytostatic drugs without IFN alpha: busulfan, hydroxyurea, 6-mercaptopurine or etoposide (VP-16). Fifty four of 102 (52.9%) patients were treated with interferon alpha (IFN alpha) after cytoreductive pretreatment. Thirty out of 102 (29.4%) patients underwent stem cell transplantation (SCT): 24 - matched related donor allo-BMT, 2 - matched unrelated donor allo-BMT, 1 - partially matched related donor T-cell depleted allo-PBPCT, 1 - syngeneic allo-BMT and 2 - autologous PBPCT. Overall survival analysis revealed that 46 of the 102 (45.1%) children remained alive: 5/35 (14.3%) children treated with cytostatics alone, 22/37 (59.5%) children treated with IFN alpha and 19/30 (63.3%) children treated with SCT. Among SCT survivors there are 10/17 (58.8%) children treated with IFN alpha prior to SCT and 9/13 (69.2%) children treated with cytostatics alone prior to SCT. The probability of 5-year survival is 0.51 in the group treated with SCT (median follow-up 58 months); 0.43 in the group treated with IFN alpha (median follow-up 53 months) and 0.23 in the group treated with cytostatics (median follow-up 31 months). Our data show, that BMT is the treatment of choice in CML in children. IFN alpha could be successfully applied as an alternative treatment for those, who do not have a suitable donor for allogeneic SCT. Better outcome in post BMT children, who were not treated with IFN alpha prior to SCT requires confirmation by studies on larger groups of patients. However, it seems to be justified to stop IFN alpha therapy at least 3 months before SCT. The main reason for unsuccessful treatment outcome in patients with CML in Poland remains the still insufficient access to MUD-BMT.