RESUMO
A 66-year-old man was injured in the traffic accident and showed the signs of hemorrhagic shock. His blood type was Rh negative O. As excessive bleeding was going on, we decided to transfuse 8 units of Rh-incompatible type O red blood cell (RBC) without performing cross match test according to the guideline for treatment of critical bleeding. Though we were aware of the risks of that treatment, no hemolytic reaction nor any other side effect was observed during and after the transfusion. Anti-Rh antibody was not developed either while Anti-Rh immunoglobulin was not given to him. His blood type has been proved to be Del type red blood cell. We conclude that transfusion of Rh-incompatible blood in patient with critical hemorrhage should be encouraged to save life.