Patients with genetic or heritable aortic conditions and thoracic aortic aneurysm syndrome often develop cardiovascular abnormalities originating at the aortic root and affecting the entire thoracoabdominal aorta. Although thoracic endovascular aortic repair (TEVAR) is usually avoided in these patients, TEVAR may be worthwhile for those at high risk for surgical complications and in certain emergency circumstances. We explored indications for TEVAR in patients with suspected or confirmed genetic or heritable aortic conditions and investigated early and mid-term outcomes. Our institutional aortic surgery database was queried for patients with suspected or confirmed Marfan syndrome, Loeys-Dietz syndrome, Ehlers-Danlos syndrome, Turner syndrome, neurofibromatosis, or familial aortic aneurysm and dissection who underwent TEVAR between February 1, 2002 and October 31, 2020. We extracted operative details and in-hospital, follow-up, and survival data. Thirty-seven patients who underwent 40 endovascular interventions met the inclusion criteria; 25 previously underwent ascending aorta or aortic root surgery, and 21 previously underwent open thoracoabdominal surgery. Postoperative complications included respiratory failure (24.3%), cardiac complications (16.2%), renal failure (13.5%), tracheostomy (8.1%), and spinal cord ischemia (paraplegia/paraparesis) (8.1%). Follow-up ranged from 1.3 to 8.5 years (median: 3.6 years), with 15 deaths overall (three early/in-hospital). Thirteen patients (35.1%) had 22 repeat interventions (open and endovascular) post-TEVAR; five had the endograft removed. Despite consensus that thoracic aneurysms in patients with genetic or heritable aortic conditions should be treated with conventional open surgery, the outcomes from our study suggest that TEVAR might be suitable in emergency settings or for patients in this population who are not candidates for open surgery, who are at high risk for reintervention, or who have a previously implanted Dacron graft. Nonetheless, lifelong surveillance is important for these patients after TEVAR to monitor for new dissection at distal or proximal landing zones, as repeat interventions are frequent.