A pseudoaneurysm of the proximal right subclavian artery is rare and most commonly caused by penetrating or blunt trauma. We report a case of a Marfan patient with a large iatrogenic pseudoaneurysm of the right subclavian artery, induced by a puncture lesion during central venous catheter placement for an elective endovascular thoracic aortic procedure. The patient was successfully treated with a hybrid approach, which consisted of endovascular coiling and balloon occlusion of the adjacent vessels, followed by open surgical exploration and uneventful closure of the puncture hole with the use of bovine pericardium-reinforced sutures.