Retroperitoneal hematoma is an obligatory complication in pelvic ring fracture.1 In most cases, the bleeding originates from venous vessels of the presacral plexus, small arteries and veins from fracture fragments. External fixation of the pelvis can control blood loss by reducing diastasis and dramatically decreasing the volume of the pelvis. But this tamponade effect can not prevent the presence of hematoma in the adjoining retroperitoneal space. It is well known that complication of retroperitoneal hematoma is infection and sepsis.