Background: Despite recent advances in the management of severe hepatic injuries, the operative mortality rate of grade V hepatic injuries still ranges from 67% to 80%. Grade V hepatic injuries involving the retrohepatic cava or main hepatic veins are almost always lethal, especially those from blunt trauma, The purpose of this study is to understand the risk factors determining operative mortality in grade V blunt hepatic trauma, and to try to improve the surgical management of these injuries, Methods: A retrospective study was conducted at a medical center that offers services including primary, secondary, and tertiary care. Forty-four patients with grade V blunt hepatic injuries were treated during a 6-year period from January 1, 1991, to December 31, 1996, The operative mortality was compared by a multivariate analysis. Results: Forty-four patients with grade V blunt hepatic injuries were identified, Seven patients had only parenchymal injuries, and the others had vascular and associated parenchymal injuries. Venorrhaphy was used in 37 patients; 29 were treated using a nonshunting approach, and 8 with an atriocaval shunt, The overall mortality rate was 68% (30 of 44), and liver-related mortality was 50% (22 of 44), Univariate analysis revealed that the significant variables affecting operative mortality were initial systolic blood pressure, initial base deficit, the Glasgow Coma Scale, injury type, number of resected segments, and total intraoperative blood loss. Based on forward step-ping logistic regression analysis, patients with an initial base deficit of -6 mmol/L or less (relative risk = 17.3), and a total intraoperative blood loss of 5,000 mt or more (relative risk = 23.5) would, significantly, encounter a worsening prognosis. Conclusions: Initial base deficit and total intraoperative blood loss were the significant factors that determined operative mortality after grade V blunt hepatic trauma. We suggest that prompt resuscitation and expeditious and appropriate surgical management, to control operative blood loss, is the only way to reduce operative mortality in patients with grade V blunt hepatic trauma.