Isolated iliac aneurysms are rare, and their management becomes complex when accompanied by ectopic pelvic kidneys due to altered vascular anatomy. We report a 58-year-old male with an incidentally discovered 53.5 mm left common iliac artery (CIA) aneurysm and an ectopic pelvic kidney. The main renal artery originated from the left proximal CIA, with two smaller polar arteries arising from the left internal iliac artery (IIA). The aneurysm was treated endovascularly with two Gore Excluder iliac limbs and coil embolization of the IIA, successfully excluding the aneurysm while preserving renal circulation. Postoperative creatinine levels remained stable, and follow-up imaging showed no complications. This case highlights the challenges of treating iliac aneurysms in patients with ectopic kidneys, where renal perfusion and adequate sealing are crucial. Endovascular techniques, including stent grafts and IIA embolization, offer safe and effective options for such complex cases.