Background <p>Idiopathic isolated aneurysms in pediatric patients are rare and present significant diagnostic and therapeutic challenges owing to their low incidence, small anatomical size, and the associated risks of injury to surrounding structures. Timely diagnosis and the selection of the most appropriate intervention require careful consideration.</p> Case presentation <p>An 11-year-old Persian boy presenting with abdominal pain for 2 months before admission was diagnosed with an isolated left internal iliac artery aneurysm through computed tomography imaging. He underwent open surgery for excision of the aneurysm. The iliac vein was adherent to the aneurysmal sac and significantly compressed, complicating the dissection and exploration. Nevertheless, proximal control was achieved, and the iliac vein was gradually separated and decompressed, allowing for the safe excision of the aneurysmal sac. The surgery was completed without intraoperative or postoperative complications.</p> Conclusion <p>Successful surgical intervention in pediatric patients with iliac artery aneurysms is achievable with careful planning and technique. This case report demonstrates the effectiveness of surgical management, with the patient remaining asymptomatic and showing no signs of recurrence during follow-up.</p>