Six studies (855 patients) were identified to investigate the therapeutic effects of iron supplementation for elderly patients undergoing hip or knee surgery. These patients were found to have increased hemoglobin levels following iron supplementation. However, there were no significant differences on the length of hospital stay, morbidity, 1 month mortality, infection rate, the rate and volume of allogeneic blood transfusions, and the adverse drug effects between patients who received additional iron and those without. Therefore, iron supplementation was found to be safe and effective in treating anemia for elderly patients undergoing hip or knee surgery.