Acute mesenteric ischemia (AMI) is a serious disease in old age with low incidence but with a very high mortality rate (60-70%). The etiology is either primary (embolism or thrombosis of mesenteric arteries or veins, non-occlusive mesenteric ischemia) or secondary (mechanical obstruction such as intestinal volvulus, intussusception, tumor-caused compression). Independent of the origin of the illness, the clinical-pathological picture is the same: intestinal ischemia with subsequent necrosis. The aim of this study was to ascertain which underlying conditions lead to increased probability of development of acute mesenteric ischemia.Two hundred and fifteen patients with a primary form of AMI were treated in the years 1991-2007, in the 1st Clinic of Surgery in Brno, Czech Republic and in the Department of General Surgery, Derer's University Hospital in Bratislava, Slovak Republic; the results of the treatment have been statistically evaluated.The probability of arterial mesenteric ischemia development rises significantly (p < 0.05) in patients with a history of atrial fibrillation and/or myocardial infarction. This probability is also significantly higher in smokers with symptoms of hypertension and clinical signs of abdominal angina (p < 0.05).