Objective The objective of this study is to report the medium-term results of GORE® EXCLUDER® Iliac Branch Endoprosthesis (IBE, W. L. Gore & Associates, Flagstaff, Ariz) for the treatment of aortoiliac aneurysms by using the GALIBER registry. Methods Patients with aortoiliac or isolated common iliac/hypogastric aneurysms treated with Iliac Branch Endoprosthesis device between January 2014 and May 2019 were prospectively collected from 5 centers. Demographic, clinical, and radiologic data were extracted from electronic databases. Technical success was defined as successful implantation of the Iliac Branch Endoprosthesis device with exclusion of aortoiliac aneurysm, as well as patency of Iliac Branch Endoprosthesis in the follow-up. Iliac Branch Endoprosthesis patency was evaluated by Doppler ultrasound and/or computed tomography based on the protocol of each participant center. Follow-up was 731 days +/− 499. Results Between January 2014 and May 2019, 105 iliac arteries were treated with GORE® IBE device, in 81 patients (79 men, two women; mean age 71, range 52–91). Only seven patients (8.6%) were symptomatic. 60 patients (74%) had aortic and iliac enlargement. Thirty-three patients presented bilateral iliac aneurysms (40.7%): In twenty-four (29.6%) patients, an Iliac Branch Endoprosthesis device was implanted in both sides, and in nine patients (11.1%), one Iliac Branch Endoprosthesis was used with the embolization of the contralateral hypogastric artery. Technical success was achieved in the 99% (104/105 iliac branch device implanted). There were no procedural deaths or type I or III intraoperative endoleaks observed. During the follow-up (range 55–1789 days), 28 (34.5%) type II endoleaks were observed and one (1.2%) type Ia was observed. The patency of the hypogastric arteries treated with the iliac branch device was 98.1% during the follow-up (range 55–1789 days). In 30% of the patients with contralateral hypogastric embolization, some kind of complications was observed in the embolizated side: one developed ischemic colitis and two buttock claudication. Conclusions Preservation of internal iliac artery with the Iliac Branch Endoprosthesis device can be performed safely with excellent technical success and good medium-term patency rates. These results support hypogastric preservation whenever possible to prevent ischemic complications.