Transfusions are among the most common medical procedures in the intensive care unit. Several randomized controlled trials (RCT) indicate that restrictive red cell transfusion practice using a haemoglobin of <7g/dL is safe in critically-ill patients. Although similar RCT are not available for plasma or platelet transfusion guidelines, a large body of observational studies suggest that plasma transfusion for an invasive procedure has not been shown to be of benefit in patients with INR <2.0. Similarly, in thrombocytopenic patients, the target platelet count for bleeding or for an invasive procedure is 50,000/µl. Viral transmission risk has become exceedingly low. Other risks such as transfusion-associated circulatory overload and, to a lesser extent, transfusion-related acute lung injury, are much more common. Storage of red cells does not seem to be associated with adverse clinical outcomes. Alternatives using haemostatic agents, salvaged blood, and adherence to evidence-based transfusion guidelines probably reduce the need for transfusion in critically-ill patients.