Intrathoracic segment of the subclavian artery is a rare location for a peripheral arterial aneurysm. A young man presented with hoarseness of voice, diminished pulses in right upper limb and superior mediastinal widening on X-ray chest. Computed tomography (CT) scan revealed an aneurysm of right subclavian artery with thrombus in its wall. Surgical repair of the aneurysm was carried out due to risk of rupture.