Critically ill patients are anemic early in their intensive care unit (ICU) course. As a consequence of this anemia they receive a large number of red blood cell (RBC) transfusions. There is little evidence that “routine” transfusion of stored allogeneic RBCs is beneficial to critically ill patients and may in fact be associated with worse clinical outcomes. It is clear that most critically ill patients can tolerate hemoglobin levels as low as 7 g/dl and therefore a more conservative approach to RBC transfusion is warranted. Strategies to minimize loss of blood and increase the production of RBCs are also important in the management of all critically ill patients.