A retrospective analysis of the clinical features of 62 patients with various hematological or other diseases who received allogeneic stem cell transplantation (SCT) between April 1990 and July 2002 in the Department of Pediatrics, Kobe University Hospital was conducted to investigate prognostic factors of allo-SCT. Among 62 allo-SCT, 51 (82%) were bone marrow transplantation (BMT), 5 (8%) were peripheral blood stem cell transplantation and 6 (10%) were cord blood transplantation. Disease-free survival rate (DFS) estimated according to the diagnosis group did not show any significant difference. For hematological malignant diseases, DFS estimated according to the disease stage was 66.7% for the patients in the standard stage and 30.0% for the patients in the advanced stage (p=0.0249). Of 47 evaluable patients receiving allo-BMT, DFS of patients receiving the last transfusion of platelets on or before day 21 was significantly higher than that of patients receiving the last transfusion after day 21 (66.7% vs 34.8%, p=0.0111). These results demonstrate that more appropriate indications and points for SCT should be applied to patients in the advanced stage, and that whether the last transfusion of platelet is on or before or after day 21 is an important prognostic factor for allo-BMT because the necessity for platelet transfusion was vividly reflected in the status of the patients.