Injury to the supraaortic artery is a rare event, with poor prognosis and high mortality. Improvement of the outcome may lie on the combination of several aspects, including better pre-hospital care, use of emergency cardiopulmonary bypass (CPB), improved surgical techniques and facilities, and advanced postoperative intensive care. Some researchers emphasized the importance of emergency CPB in the treatment and thought that it was responsible mainly for the improved outcome. However, there exists controversies about it. In this article, we reported that a patient with life-threatening hemorrhage due to traumatic transection of the left common carotid artery, who was admitted to our hospital in July 2003, was treated successfully with operations with help of emergency CPB and systemic hypothermia.