The use of massive transfusion protocols (MTPs) in trauma patients presenting with near-exsanguinating injuries has increased in the past several years. This is largely a result of the increasing evidence suggesting that transfusion of blood components in ratios more closely approximating the composition of whole blood may reduce mortality.1–4 Inherent in the design of these protocols is the necessity for the timely transfusion of plasma. Unfortunately, the need for plasma often precedes the determination of blood group.