Background —Iliac artery aneurysms have traditionally been treated by direct surgical reconstruction. Endovascular stent grafts have been developed to provide an effective but less invasive treatment option for patients with peripheral arterial aneurysms. Methods and Results —In 48 patients, a total of 53 endoprostheses (mean length 7.3 cm, mean diameter 8.1 mm) were implanted into the iliac arteries (common iliac artery n=29, external iliac artery n=19) for percutaneous exclusion of aneurysmal lesions. The technical success of complete exclusion of the aneurysm was achieved in 47 of 48 cases (97.9%). In 1 case, persistent perfusion through a collateral branch was detected; however, this aneurysm thrombosed spontaneously within 2 weeks. In all patients, graft patency was monitored by clinical examination, which included the standardized treadmill test with calculation of the ankle-brachial Doppler index and color-coded duplex ultrasound. Forty-two of the 48 patients (87.5%) underwent follow-up angiography. According to Kaplan-Meier life-table calculations, primary patency rates were 100% after 1 year, 97.9% after 2 years, 94.9% after 3 years, and 87.6% after 4 years. Serial contrast-enhanced spiral CT scans were performed to rule out late procedural failures and to assess growth progression of the lesions. No secondary leaks were observed. Furthermore, the aneurysm diameter had reduced from 24.8±8.0 mm to 23.1±6.6 mm at the last follow-up ( P =NS). Conclusions —Stent grafts are a safe and effective treatment option for iliac artery aneurysms and provide good long-term patency of the graft.