Between 1964 and 1978 twenty patients suffering from acute mesenteric vascular occlusion were treated in the surgical department (University of Münster). The average duration of the anamnesis until their hospitalization was 3.1 days and the actual operation was performed 11.35 hours later on the average. In only 15% of the cases had a correct preoperative diagnosis been given. As regards the frequency of causation, 60% of the mesenteric vascular occlusions were caused by a mesenteric arterioembolism, 20% by a mesenteric venous embolism, 10% by a mesenteric arterial thrombosis and 10% by a non-obstructive occlusion. In a post cardiac infarction condition was the predisposing factor in 50% of all cases, valvular defect in 33.5% and tachyarrhythmia in 16.6%. The causes found for the mesenteric venous tbrombosis were insufficiency of the right heart, absolute bradyarrhythmia, recurrent venous thrombosis of the leg, and myeloproliferative syndromes.