Introduction: Arteriovenous fistulas (AVF) of the superior mesenteric vasculature are rare vascular abnormalities. It often occurs due to iatrogenic injuries during bowel resection or abdominal traumas. As the patient exhibits a variety of signs and symptoms and can present late, diagnosis may be difficult. Multidetector computed tomography (MDCT) is the most common modality for imaging the small bowel, vessels, and mesentery in patients with mesenteric ischemia. Case presentation: We present the case of a 25-year-old man who presented with features of acute intestinal obstruction and was operated on in an emergency. Resection of gangrenous small bowel and bowel adhesiolysis with double barrel ileostomy was performed. During exploratory laparotomy, gangrenous bowels were found, but no cause of mesenteric ischemia could be delineated. Finally, on computed tomography angiography (CTA) superior mesenteric arteriovenous fistula (SMAVF) with superior mesenteric vein (SMV) thrombosis was diagnosed. The patient was advised of aggressive anticoagulant therapy. Conclusion: Computed tomography angiography has become the most reliable diagnostic modality to confirm the diagnosis and guide the best treatment strategy.