The overall use of allogeneic blood transfusions in clinical practice remains relatively high and still varies widely among centres and practitioners. Moreover, allogeneic blood transfusions have historically been linked with risks and complications: some of them (e.g. transfusion reactions and transmission of pathogens) have been largely mitigated through advancements in blood banking whereas some others (e.g. immunomodulation and transfusion--related acute lung injury) appear to have more subtle aetiologies and are more difficult to tackle. Furthermore, blood transfusions are costly and the supply of blood is limited. Finally, evidence indicates that a great number of the critically ill patients who are being transfused today may not be having tangible benefits from the transfusion. Patient blood management is an evidence--based, multidisciplinary, multimodal, and patient--tailored approach aimed at reducing or eliminating the need for allogeneic transfusion by managing anaemia, perioperative blood conservation, surgical haemostasis, and blood as well as plasma--derivative drug use. From this point of view, the reduction of allogeneic blood usage is not an end in itself but a tool to achieve better patient clinical outcome. This article focuses on the three--pillar matrix of patient blood management where the understanding of basic physiology and pathophysiology is at the core of evidence--based approaches to optimizing erythropoiesis, minimising bleeding and tolerating anaemia. Anaesthesiologists and Critical Care physicians clearly have a key role in patient blood management programmes are and should incorporate its principles into clinical practice--based initiatives that improve patient safety and clinical outcomes.