Granulocytes for transfusion can now be obtained from normal donors by one of four techniques that involve either centrifugation or reversible adhesion of granulocytes to nylon fibers. The leukapheresis process appears to be safe for donors and standards for the selection and care of donors are being formulated. It appears desirable to transfuse granulocytes that are compatible in a leukoagglutination crossmatching, however, better methods for histocompatibility testing must be developed. Granulocyte transfusions clearly are of benefit to patients with Gram-negative sepsis and granulocyte counts of less than 500/cu mm for at least ten days. They may be valuable for granulocytopenic patients with other severe infections; however, there is no indication that granulocyte transfusions are indicated prophylactically or for febrile granulocytopenic patients without evidence of infection.