Although, depending on the timescale before surgery, oral iron is suggested for preoperatively anaemic patients with absolute iron deficiency, oral iron showed no benefit over placebo in anaemic patients after lower limb arthroplasty. In patients at risk of functional iron deficiency due to chronic inflammation of different aetiologies, intravenous (i.v.) iron administration has proven its superiority over oral iron. Even in iron-deficient patients without established anaemia, i.v. iron improved physical performance and cardiac functional class. Thus, postoperative anaemia treatment with i.v. iron might not only reduce RBC requirements but also improve performance, rehabilitation and outcomes.