Objective The treatment of patients with arch and thoracoabdominal aortic aneurysms (TAAAs) and chronic dissections is challenging. We report the results of fenestrated and branched endovascular aortic repair (FEVAR) of such aneurysms. Methods A single-center prospective FEVAR trial enrolled 356 patients (2006 to 2011), of whom 30 had chronic dissections with arch aneurysm or TAAAs, or both. Patients were divided into group A, 15 patients (mean age, 58 years) with extensive dissections extending from the arch through the visceral segment, and group B, 15 patients (mean age, 74 years old) with focal dissections and no extension into the thoracic aorta. Inclusion criterion was aneurysm size >5.5 cm in diameter. Customized grafts were implanted into the true lumen, and branches were extended into the true lumen of the supra-aortic trunk (arch branch devices) and visceral vessels. Patients were monitored annually with clinical, imaging, and laboratory studies. Outcome analyses included survival, rupture, spinal cord ischemia, endoleak, morbidity (cardiac, renal or pulmonary), reinterventions, dissection, and aneurysm growth. Results The mean time from the onset of dissection to the FEVAR performed in group A was 10.4 years. The mean maximum aneurysm diameter was 60 mm. Follow-up averaged 1.7 years. There were no perioperative deaths. One aortic-related death occurred at 87 days due to progression of a pre-existing untreated arch dissection. No ruptures, cardiac, renal, pulmonary, or spinal cord ischemia complications occurred. Despite the initially narrow true lumen dimensions, stent grafts expanded to their nominal diameters after implantation without any blood flow disturbance of branched visceral vessels and distal aorta. No graft compression occurred. Post-FEVAR growth was noted in two patients, related to type II endoleaks. Sac regression was similar (−6.8 vs −11.4 mm; P = .43), but early endovascular reinterventions were more common in group A (8 patients). Patients with extensive dissection were younger, and the dissection more likely to be associated with a defined connective tissue disease (Marfan syndrome or Loeys-Dietz mutations, 40% vs 0%; P = .006). Conclusions FEVAR is feasible for patients with chronic dissections and TAAA. Concerns regarding visceral vessel access and graft compression resulting from narrow true lumen diameters were not relevant in our experience. Favorable sac and lumen morphologic changes, coupled with a low mortality and complication risk, makes this an attractive means of handling this clinical problem.