This EBMT activity survey presents the status of hematopoietic stem cell transplantation (HSCT) in Europe 2003 and focuses on changes in stem cell source over the last decade. There were 21 028 first HSCT, 7091 allogeneic (34%), 13 937 autologous (66%) and 4179 additional re- or multiple transplants reported from 597 centers in 42 European countries in the year 2003. Main indications were leukemias (6613 (31%; 78% allogeneic)); lymphomas (11 571 (55%; 93% autologous)); solid tumors (1792 (9%; 92% autologous)) and nonmalignant disorders (898 (5%; 93% allogeneic)). In 1991, the vast majority of autologous and all allogeneic HSCT were still bone marrow (BM) transplants. Stem cell source changed rapidly to peripheral blood (PB) for autologous HSCT between 1992 and 1996. In 2003, 97% of autologous HSCT were PB derived. The change to PB for allogeneic HSCT followed 3 years later and occurred at a lower rate. In 2003, 65% of all allogeneic HSCT were PB derived. The change in stem cell source was not homogeneous. It was associated with donor type, main diagnosis, disease stage and it differed between European countries. In 2003, bone marrow remains a significant source of stem cells in some European countries for autologous HSCT and for nonmalignant disorders in allogeneic HSCT.