Abstract Homologous transfusion carries a 5 per cent risk of transfusion reaction, a 0.5 per cent risk of overt hepatitis, and a 0.05 per cent risk of hepatitis-associated death. Autologous transfusion eliminates all of these risks and serves as an additional supply of blood. Fifty patients donated blood preoperatively for possible later autologous transfusion. Twelve of these patients received autologous blood only, and two patients received 1 unit of autologous blood and 2 units of homologous blood. Although carried out only once in this study, if iron stores are adequate and the hemoglobin level is above 11 gm/100 ml, 2 units or more can be drawn preoperatively with equal safety. No adverse effects were noted in these patients. If one or more transfusions might be required during an elective surgical procedure, banked autologous blood is completely safe and should be utilized whenever possible. Recent changes in the regulations governing blood banks make this feasible, and good medical practice makes it desirable.