Inferior mesenteric artery aneurysm is very rare and are usually asymptomatic. A high mortality is associated with aneurysmal rupture. The purpose of this paper is to report occurrence of a rare disease and its treatment options. A 64 years old woman presented with complaints of lower abdominal pain radiating to back for 1month, with non-passage of stools for 5days, and had decreased appetite. She had features of Neurofibromatosis type I. On examination, she had tachycardia and had pallor, and abdominal examination showed lumps in right and left iliac fossa which progressively increased in size. Computed tomography scan showed features of leaking inferior mesenteric artery aneurysm with perianeurysmal hematoma. The patient was taken up for surgical exploration wherein after checking the bowel viability, the inferior mesenteric artery was clipped at its origin, ligated and divided followed by hematoma evacuation. Post-operative stay was uneventful, and the patient was discharged on post-operative day 10.