Purpose: To determine long-term results of the prospective Dutch Iliac Stent Trial. Materials and Methods: The study protocol was approved by local institutional review boards. All patients gave written informed consent. Two hundred seventy-nine patients (201 men, 78 women; mean age, 58 years) with iliac artery disease were randomly assigned to undergo primary stent placement (143 patients) or percutaneous transluminal angioplasty (PTA) with selective stent placement in cases in which the residual mean pressure gradient was greater than 10 nun Hg across the treated site (136 patients). Before and at 3, 12, and 24 months and 5-8 years after treatment, all patients underwent assessment, which included duplex ultrasonography (US), ankle-brachial index (ABI) measurement, Fontaine classification of symptoms, and completion of the Rand 36-Item Health survey for quality-of-life assessment. Treatment was considered successful for symptoms if symptoms increased at least one Fontaine grade, for ABI if ABI increased more than 0.10, for patency if peak systolic velocity ratio at duplex US was less than 2.5, and for quality of life if the RAND 36-Item Health Survey score increased more than 15 points. Effects of both treatments on symptoms, quality of life, patency, and ABI were compared by using survival analyses. Results: Patients who underwent PTA and selective stent placement had better improvement of symptoms (hazard ratio [HR], 0.8; 95% confidence limits [CLs]: 0.6, 1.0) than did patients treated with primary stent placement, whereas ABI (HR, 0.9; 95% CLs: 0.7, 1.3), iliac patency (HR, 1.3; 95% CLs: 0.8, 2.1), and score for quality of life for nine survey dimensions did not support a difference between treatment groups. Conclusion: Patients treated with PTA and selective stent placement in the iliac artery had a better outcome for symptomatic success compared with patients treated with primary stent placement, whereas data about iliac patency, ABI, and quality of life did not support a difference between groups. (c) ...