Granulocyte replacement therapy for the infected patient with severe neutropenia is effective in improving the short-term and possibly the long-term prognosis. The best methods of procuring and administering granulocytes still are under investigation, and no reliable method for predicting compatibility has been developed. At present granulocyte transfusion therapy is indicated for severely neutropenic patients with documented infection as an adjunct to antibiotic therapy. It should be used only at institutions that offer the necessary professional and technical skills to minimize danger and discomfort to both donor and recipient as well as the expense of the treatment.