Abstract Background Acute mesenteric ischemia (AMI) is rare, and few large-scale trials have evaluated endovascular therapy (EVT) and open surgical revascularisation (OS). This study aimed to assess clinical outcomes after EVT or OS for acute superior mesenteric artery occlusion (SMAO) and identify predictors of mortality and bowel resection. Methods Data from the Japanese Registry of All Cardiac and Vascular Diseases-Diagnosis Procedure Combination database from April 2012 to March 2020 were retrospectively analyzed. Overall, 746 patients with acute SMAO who underwent revascularisation were classified into two groups: EVT (n=475) or OS (n=271). The primary clinical outcome was in-hospital mortality. The secondary outcomes were bowel resection, bleeding complications (transfusion or endoscopic hemostasis), major adverse cardiovascular events (MACEs), hospitalisation duration, and cost. Results The in-hospital death or bowel resection rate was approximately 30%. In-hospital mortality (22.5% vs. 21.4%, p=0.72), bowel resection (8.2% vs. 8.5%, p=0.90), and MACEs (11.6% vs. 9.2%, p=0.32) were comparable between the EVT and OS groups, respectively (Table.1). EVT was advantageous in terms of hospitalisation duration and cost (both p<0.0001). Interaction analyses revealed that EVT and OS had no significant difference in terms of in-hospital death in patients with thromboembolic and atherothrombotic characteristics (Figure.1). Multivariate logistic regression analysis revealed that advanced age, decreased activities of daily living, chronic kidney disease, and old myocardial infarction were significant predictive factors for in-hospital mortality. Diabetes Mellitus was a predictor of bowel resection after revascularisation. Conclusions EVT was comparable to OS in terms of clinical outcomes in patients with acute SMAO. Some predictive factors for mortality or bowel resection were obtained. Clinical implications EVT may be a feasible alternative to OS, potentially impacting clinical practice as a less invasive option for managing patients with acute SMAO.In-hospital clinical outcomesInteraction effect test for mortality