Acute mesenteric ischemia represents an intensive medical emergency which, when untreated, leads to sepsis and multiorgan failure. Predictive factors for survival are the time duration between onset of symptoms and therapy, etiology,patient age, and immediate therapy with anticoagulants in case of acute mesenteric thrombosis. Pathologically raised laboratory parameters (lactate, acidosis, leukocytosis) are signs of advanced mesenteric ischemia. Therapy aims at reinstating arterial perfusion of ischemic and potentially life-threatening intestinal regions and at avoiding further ischemias or infarctions. Immediate vessel reconstruction (embolectomy, thrombectomy,TEA,bypass) can prevent mesenteric infarction and is therefore preferable to intestinal resection alone, as long as irreversible ischemia or sepsis are not present. If the degree of reperfusion is in question, the indication for "second-look laparotomy" is to be used generously.