A 46-year-old male underwent previous endovascular repair for thoracic aortic coarctaction in 2017. Five years later he underwent an angio-computed tomography that revealed a 60mm x 53mm asymptomatic saccular costocervical artery aneurysm (A, yellow arrow). An angiography was subsequently performed, and selective catheterization was possible with a triaxial microcatheter system (B, circle defining the aneurysm extension). Costocervical trunk aneurysms are very rare vascular abnormalities and usually are associated with congenital heart defects or connective tissue disorders. The case is scheduled for discussion in a multidisciplinary meeting with cardiothoracic surgery for elaboration of a treatment strategy.