Introduction: Acute mesenteric ischemia (AMI) is a rare but lethal disease. Mesenteric vein thrombosis (VAMI) is a subtype of AMI. Morbid obesity is usually accompanied by hypertension, hyperlipidemia, or diabetes mellitus, which are risk factors associated with AMI. Case Presentation: We present a 28-year-old man with VAMI post-laparoscopic sleeve gastrectomy. He was first misdiagnosed with intestinal obstruction. Superior VAMI was confirmed after computed tomography angiography. Laparotomy, resection of the necrotic small bowel, and ostomy were performed immediately. Conclusion: Patients with morbid obesity accompanied by hypertension, hyperlipidemia, or diabetes mellitus have a high risk of AMI. Abdominal pain with sudden onset should be considered AMI. Anticoagulation therapy post-sleeve gastrectomy might help reduce the incidence of AMI.