BACKGROUND Acute mesenteric artery embolism has a high rate of morbidity and mortality. Early diagnosis and appropriate treatment are the most important factors associated with morbidity and mortality. METHODS During the period between 1997 and 2002, 24 patients underwent superior mesenteric artery embolectomy. The patients were divided into three groups according to the onset of symptoms and operation time. Group I (n = 12) patients were operated on in the first 6 hours after onset of symptoms; group II (n = 9) patients were operated on between 6 and 12 hours after onset; and group III (n = 3) patients underwent embolectomy after 12 hours. Low-dose (5 to 10 mg) local tissue-type plasminogen activator (t-PA) administration directly into the superior mesenteric artery was an additional procedure with the embolectomy in all patients. RESULTS The macroscopic view of the intestine was normal in 15 patients (12 patients in group I and 3 patients in group II) 30 minutes after the administration of local t-PA. Segmental resection was necessary in 4 patients in group II. Extended resection was necessary in 2 patients in group II and 3 patients in group III, and all of the patients died during the early postoperative period. CONCLUSIONS We suggest that explorative laparotomy should be done in patients with sudden abdominal pain, nausea, vomiting, mild leukocytosis, and metabolic acidosis who have previous valvular heart disease or atrial fibrillation. Ultimately, selective low dose t-PA (5 to 10 mg) administration reduces the length of intestinal portion to be resected.