The transfusion of fresh whole blood (FWB) for trauma-induced coagulopathy is unusual in civilian practice. However, US military physicians have used FWB in every combat operation since the practice was introduced in World War I and continue to do so during current military operations. We discuss our review of all blood products administered to US military casualties in Operation Iraqi Freedom (OIF) between March and December 2003. FWB transfusions were most frequent when demands for massive transfusions wiped out existing blood supplies. FWB patients had the highest blood product requirements; however, mortality did not differ significantly between FWB and non-FWB patients overall or for massively transfused patients. We review the current military practice of FWB transfusion in combat theaters and conclude that FWB transfusion is convenient, safe, and effective in certain military situations.