In order to compare autologous bone marrow (BMT) and blood cell transplantation (BCT) in patients with acute myeloid leukemia (AML) in first remission (CR1), we retrospectively reviewed the data of 1393 patients registered to EBMT and undergoing either BCT (n = 100), purged (n = 252) or unpurged (n = 1041) BMT. Hematopoietic recovery was significantly quicker after BCT than after either purged or unpurged BMT. The 2-year leukemia-free survival (LFS), relapse incidence (RI) and overall survival for the entire population of patients were 52 +/- 1%, 43 +/- 1% and 58 +/- 1% and were significantly influenced by FAB subtype (M3 vs other) and the intervals between diagnosis and CR1 or CR1 and transplant. After BCT, LFS and RI were 44 +/- 6% and 50 +/- 6% and did not differ significantly from that found for unpurged BMT (49 +/- 2% and 45 +/- 2%; P = NS). However, LFS (57 +/- 3%) and RI (37 +/- 3%) of patients undergoing purged BMT were significantly different from that found for BCT patients (P = 0.01 and P = 0.006). As some characteristics of patients undergoing BCT or purged BMT differed significantly (age, intervals between diagnosis and CR1 or CR1 and transplant), the better outcome observed for purged BMT over BCT patients needs to be prospectively investigated.