Disseminated intravascular coagulation (DIC), experimentally induced by endotoxin, caused severe hemorrhagic necrosis of the intestinal mucosa in dogs. Microscopic observation showed tortuous thrombus formation in the microcirculation of the villi. Ligation of the pancreatic and bile ducts, or administration of heparin protected the mucosa from hemorrhagic necrosis, while systemic administration of tranexamic acid increased the intestinal mucosal lesion. Local pretreatment of the intestinal mucosa by Trasylol or tranexamic acid reduced the degree of hemorrhagic necrosis. It is concluded that intravascular coagulation in the microcirculation of the intestinal mucosa, as well as pancreatic proteases, play a role in the pathogenesis of hemorrhagic necrosis in the intestine associated with DIC.