Objectives The aim of this study is to report the safety and effectiveness of thoracic endovascular aortic repair (TEVAR) in a native proximal landing zone (PLZ) 2 for chronic type B aortic dissection (TBAD) patients with genetic aortic syndrome (GAS). Methods A retrospective review of a single center database to identify patients with GAS treated with TEVAR in native PLZ 2 for chronic TBAD and thoracic false lumen aneurysm between February 2012 and February 2018 was undertaken. Results In total, 31 patients with GAS (24 Marfan syndrome [MFS], 5 Loeys-Dietz syndrome [LDS], and 2 vascular Ehlers-Danlos syndrome [vEDS]) were treated by endovascular repair. Nineteen patients were treated by TEVAR as index procedures with 8 patients (5 females, mean age = 55, range = 36–79 years old) receiving TEVAR in native PLZ 2. Left subclavian artery (LSA) perfusion was preserved in all 8 patients: by left common carotid artery-LSA bypass in 6 patients, chimney stenting of the LSA in 1 patient, and partial coverage of LSA ostium in 1 patient. Technical success was achieved in all patients (100%). There was no 30 day mortality (0%). The 30 day morbidity (0%) was free from major complications. The median follow-up was 40 months (range = 7–79). One patient died due to non-aortic-related cause. Native PLZ 2 was free from complications in MFS patients (5/8). Two patients with LDS developed type Ia endoleak with aneurysmal progression. One patient was treated by proximal extension with a double inner branched arch stent-graft landing in the replaced ascending aorta. The other one was treated with frozen elephant trunk. Conclusion Thoracic endovascular aortic repair in native PLZ 2 was safe and effective with no early or midterm PLZ complications in patients with MFS with chronic TBAD in this limited series. Native PLZ 2 is not safe in patients with LDS and should only be used in emergencies as a bridging to open repair.