The efficacy and safety of granulocyte transfusions were evaluated in two acute lymphoblastic leukemia patients for the control of severe infections (cervical cellulitis, sepsis) prior to hematopoietic stem cell transplantation. One patient received 6 transfusions and the other 2 transfusions. The donors were given subcutaneous granulocyte-colony stimulating factor plus oral dexamethasone/betamethasone 12 hours before the scheduled collection. Granulocytes were obtained by standard leukapheresis procedures utilizing hydroxyethyl starch with processing of 7 liters of blood. The yield was 3.2-10.7 x 10(10) (0.7-2.1 x 10(9)/kg of recipient) granulocytes. Post-transfusion increases of peripheral blood neutrophil counts in the following morning were 300 to approximately 6,900/ml. Infections resolved and successful engraftment was obtained in both patients after the transplants. No severe adverse reactions were observed. These findings suggest that granulocyte transfusions are useful for control of severe infections prior to allogeneic hematopoietic stem cell transplantation.