Anemia is frequent after a surgical procedure. Postoperative anemia is associated with an increased incidence of transfusions and, probably, with an increased incidence of morbidity and mortality. However, the majority of studies evaluating the consequences of postoperative anemia are retrospective and, since anemic patients were transfused, they are unable to distinguish between the effects of anemia per se and those of transfusion. In orthopedic surgery, only two randomized controlled trials (RCT) have attempted to determine the benefits of transfusions in this patient population. The first evaluated the benefits of allogeneic transfusions in patients undergoing surgery for a fractured hip while the second evaluated autologous transfusions in patients undergoing total knee replacement. The small number of patients included in both studies did not allow definitive conclusions on the benefits (or lack thereof) of transfusions in orthopedic surgery.