Objective To investigate the effects of blood transfusion on postoperative infection in patients with breast cancer.Methods 311 patients who underwent breast cancer operations in our hospital were observed.Among them,109 patients were transfused with red blood cell (RBC) concentrates,112 with white blood cell(WBC)-depleted RBC concentrates,90 were not transfused.The rates of postoperative infection of three groups were compared.Results The rate of postoperative infection of the group transfused with RBC concentrates was 5.50%.The rate of postoperative infection of the group transfused with WBC-depleted RBC concentrates was 0.89%,which was significantly different from that of the group transfused with RBC concentrates(P0.05).Conclusions In patients with breast cancer,the rate of postoperative infection of the group transfused with RBC concentrates was higher than that of group transfused with WBC-depleted RBC concentrates and of the group without transfusion. The rate of postoperative infection was closely correlated to the amount of RBC concentrates.