Marfan syndrome is a heritable connective tissue disorder affecting skeletal, ocular and cardiovascular systems. Cardiovascular manifestations comprise aneurysmal dilatation of aortic root, aortic dissection and rupture; peripheral arterial aneurysms have been reported in femoral, iliac and subclavian arteries with surgical reconstruction as the first-line therapeutic option. We report a Marfan patient with a symptomatic aneurysm of left subclavian artery in the intrathoracic retro-clavicular space; instead of open surgical resection, an endovascular solution was successfully applied by use of a flexible self-expanding stent-graft (W.L Gore® Viabahn® Endoprosthesis 9 × 100 mm) to exclude the aneurysm. This case exemplifies a modern option to manage vascular pathology even in patients with Marfan syndrome. Follow-up over 1 year proved very reassuring with complete remodelling and resolution of the aneurysm; long-term follow-up is certainly warranted, considering the potential of recurrence or initial reactive hyperplasia.