During a 16-year period, 47 wounds of the portal and/or superior mesenteric veins were encountered. Overall mortality was 57%. Survival was greatest in patients with injury to the superior mesenteric vein, wounds repairable by lateral phleborrhaphy, absence of associated major vascular trauma, and only transient or minimal hypovolemic shock. The majority of deaths were due to uncontrollable bleeding or sequelae of profound hemorrhagic shock. Limited follow-up of survivors has demonstrated a low patency rate at the site of venous repair, suggesting that mere ligation may be all that is necessary when lateral repair is impossible.