Purpose of review: The aim of this paper is to provide the clinician an overview about the link between iron homeostasis and erythropoiesis and how we can promote this relationship in order to improve surgical patients’ outcome. Key elements: Iron is essential for various cellular processes, like cell signalling, oxygen transport, erythrocyte and heme synthesis, mitochondrial respiration, host defence, nucleic acid replication. Erythropoietin and iron are the main erythropoiesis regulators. Under iron-restricted conditions, the erythrocytes production is impaired, leading to microcytic hypochromic anemia appearance. Iron-restricted condition enables patient capacity to recover from post-surgery anemia. Long-term consequences of chronic anemia affect patient’s quality of life. Therefore, parenteral iron supplementation, in patients with anemia secondary to blood loss, can lead to a fivefold increase in erythropoietic response, therefore enhancing recovery. Summary: Under normal circumstances, the link between iron and erythropoiesis is maintained especially through regulatory feedback mechanisms, with minimal external support. In face of important blood loss, with secondary acquired iron-restricted anemia, parenteral iron supplementation improves the bone marrow erythroid response and helps correcting haemoglobin levels.