- Erythropoiesis-stimulating agents (ESAs) have been used in orthopedic patients to reduce allogeneic blood transfusion (ABT). The purpose of this systematic review of randomized clinical trials is to evaluate the efficacy of preoperative administration of ESAs on hemoglobin level at discharge and frequency of ABT in patients undergoing hip or knee surgery. Pooled results of 26 trials with 3560 participants showed that the use of preoperative ESAs reduced ABT in patients undergoing hip or knee surgery [RR: 0.48, 95% CI: 0.38 to 0.60, P<0.00001]. Hemoglobin mean difference between ESA and control groups was 7.16 (g/L) [95% CI of 4.73 to 9.59, P=0.00001]. There was no difference in the risk of developing thromboembolism between ESA and control groups [RD: 0, 95 % CI: -1%-2%, P=0.95]. ESAs offer an alternative blood conservation method to avoid ABT in patients undergoing hip or knee surgery.