Neutrophils play an essential role in the defense of the body against bacterial and fungal infections. Disorders of their number or function significantly increase the risk of life-threatening infection. In spite of the development of growth factors, new broad spectrum antibiotics and antifungal drugs against nearly all known pathogens, severe neutropenia associated with bacterial or invasive fungal infections remains a major cause of morbidity and mortality in patients undergoing aggressive cancer chemotherapy or hematopoietic stem cell transplantation. Lately, an interest about granulocyte transfusions was renewed, what is a logical approach in the management of patients with prolonged 'reversible' severe neutropenia and severe infection, which is not controlled with appropriate antimicrobial and supportive treatment, including recombinant hematopoietic growth factors. It was a consequence of advances in the field of apheresis science, use of sedimenting agents and especially advances in mobilization of granulocytes to the peripheral blood. It became now possible to collect large numbers of neutrophils. Therefore, the clinical use of granulocyte transfusions, as a potential life saving treatment option in patients with severe neutropenia and uncontrolled infection in spite of appropriate antimicrobial therapy should be considered, with regard to possible benefits and risks (Ref. 74).