A total of 201 leukaphereses have been performed on 73 donors to collect granulocytes for transfusion to infected leukopenic recipients. The pretreatment of the donor with etiocholanolone and the addition of hydroxyethyl starch to the extracorporeal circulation significantly increased the total number of granulocytes collected. Adverse side effects were minimal. The majority of donors underwent the procedure on 13 occasions over a period of eight weeks. Follow‐up donors two or more years later has revealed no long‐term adverse side effects from leukapheresis or from the addition of etiocholanolone and hydroxyethyl starch. 1974 AABB