Objective In this study, we analyzed the procedural success and early outcome of endovascular treatment of a multicenter cohort of patients with common iliac artery (CIA) aneurysms treated with the new GORE EXCLUDER (W. L. Gore & Associates, Flagstaff, Ariz) iliac branch endoprosthesis (IBE). Methods A retrospective cohort analysis was performed in 13 sites in The Netherlands. Anatomic, demographic, procedural, and follow-up data were assessed from hospital records. Results From November 2013 to December 2014, 51 CIA aneurysms were treated with an IBE in 46 patients. The median diameter of the treated aneurysm was 40.5 (range, 25.0-90.0) mm. The mean procedural time was 198 ± 56 minutes. All but one implantation were successful; two type Ib endoleaks were noticed, resulting in a procedural success rate of 93.5%. The two type Ib endoleaks spontaneously disappeared at 30 days. There was no 30-day mortality. Ipsilateral buttock claudication was present in only two cases at 30 days and disappeared during follow-up. The incidence of reported erectile dysfunction was low and severe ischemic complications were absent. After a mean follow-up of 6 months, data on 17 treated aneurysms were available. Two showed a stable diameter, whereas 15 showed a mean decrease of 3.9 ± 2.2 mm (P <.001). Reinterventions were performed in two patients (7.1%). The 6-month primary patency of the internal component of the IBE device was 94%. Conclusions The use of the GORE EXCLUDER IBE device for CIA aneurysms is related to high procedural success, high patency rates, and low reintervention rates at short-term follow-up. Prospective data with longer follow-up are awaited to establish the role of the device in the treatment algorithm of CIA aneurysms.