Abdominal pain is one of the most common presenting complaints to the emergency department. Mesenteric venous thrombosis represents an important cause to consider in patients with acute abdominal pain. The diagnosis is often delayed, and cases traditionally have been identified either at laparotomy or at autopsy. In this case, we describe a 21-year-old female with acute onset of right lower quadrant pain attributable to a hyperhomocysteinemia related non-occlusive superior mesenteric vein thrombosis. This case highlights how the use of computed tomography in select cases can lead to earlier recognition of this condition and increasingly allow for non-surgical treatment. [West J Emerg Med 2011;12(2):262-265.]