Between 1972 and 1993 a total of 90 patients were operated on for acute mesenteric ischemia at Hanover Medical School, Department of Abdominal- and Transplantation Surgery. As causes of mesenteric ischemia, arterial embolism (23%), arterial thrombosis (30%), venous thrombosis (33%), and non-occlusive disease (14%) were differentiated. The overall hospital mortality was 66%. The hospital mortality after venous thrombosis was 37%, significantly lower than after arterial (79%) and functional(83%) types of mesenteric ischemia. Besides the pathogenesis of mesenteric infarction, a multivariate analysis revealed age and presence of peritonitis and intestinal perforation to be independent prognostic factors of hospital lethality. Patients with venous thrombosis had a mean age of 48 years and were significantly younger than the remaining patients who had an average age of over 60 years. Surgical procedures comprised solitary bowel resection (60%), isolated embolectomy and/or thrombectomy (10%), a combination of embolectomy/thrombectomy and bowel resection (4%), and exploratory laparotomy only (21%). Vascular reconstruction was associated with a significantly better survival rate than bowel resection only. While hospital mortality was dependent on the type of mesenteric ischemia, long-term survival after exclusion of hospital deaths proved independent of the original pathogenesis. Of the patients who survived the acute attack of mesenteric ischemia, 70% were alive 2 years later and 50% 5 years later. The survival probability of these patients was not determined by recurrence of mesenteric ischemia, but was mainly related to their cardiovascular comorbidity and a high incidence and prevalence of malignancies.