To delineate blood transfusion practices and outcomes in patients with major burn injury. Patients with major burn injury frequently require multiple blood transfusions; however, the effect of blood transfusion after major burn injury has had limited study. Multicenter retrospective cohort analysis. Regional burn centers throughout the United States and Canada. Patients admitted to a participating burn center from January 1 through December 31, 2002, with acute burn injuries of >or=20% total body surface area. Outcome measurements included mortality, number of infections, length of stay, units of blood transfused in and out of the operating room, number of operations, and anticoagulant use. A total of 21 burn centers contributed data on 666 patients; 79% of patients survived and received a mean of 14 units of packed red blood cells during their hospitalization. Mortality was related to patient age, total body surface area burn, inhalation injury, number of units of blood transfused outside the operating room, and total number of transfusions. The number of infections per patient increased with each unit of blood transfused (odds ratio, 1.13; p<.001). Patients on anticoagulation during hospitalization received more blood than patients not on anticoagulation (16.3+/-1.5 vs. 12.3+/-1.5, p<.001). The number of transfusions received was associated with mortality and infectious episodes in patients with major burns even after factoring for indices of burn severity. The utilization of blood products in the treatment of major burn injury should be reserved for patients with a demonstrated physiologic need.