Purpose: To evaluate the efficacy, feasibility, and long-term outcomes of the Zenith ZBIS iliac branch device (IBD) to preserve internal iliac artery (IIA) perfusion in a large Dutch multicenter cohort. Methods: Between September 2004 and August 2015, 140 patients (mean age 70.9±7.4 years; 130 men) with 162 IBD implantations were identified in 7 vascular centers. The indication for IBD implantation was an abdominal aortic aneurysm >55 mm with a concomitant common iliac artery (CIA) aneurysm >20 mm (n=40), a CIA aneurysm with a diameter >30 mm (n=89), or revision of a type Ib endoleak after endovascular aneurysm repair (n=11). Results: Technical success (aneurysm exclusion, no type I or III endoleak, and a patent IIA) was obtained in 157 (96.9%) of 162 IBD implantations. Six (4.3%) patients developed major complications; 2 (1.4%) died. Mean follow-up was 26.6±24.1 months, during which 17 (12.1%) IBD-associated secondary interventions were performed. Including technical failures and intentional IIA embolizations, 15 (9.3%) IIA branch occlusions were identified; buttock claudication developed in 6 of these patients. The freedom from secondary intervention estimate was 75.9% (95% confidence interval 59.7 to 86.3) at 5 years. Conclusion: CIA aneurysms can be treated safely and effectively by IBDs with preservation of antegrade flow to the IIA. Secondary interventions are indicated in >10% of patients during follow-up but can be performed endovascularly in most.