Intrathoracic segment of the subclavian artery is an unusual location for peripheral arterial aneurysms. They are normally caused by atherosclerosis, medial degeneration, trauma, and infection. We report a case of a patient with right subclavian artery aneurysm presenting with hoarseness. Chest radiograph demonstrated a superior mediastinal mass. Laryngoscopy showed a fixed right vocal cord. By chest computed tomography, magnetic resonance imaging, and angiography, preoperative diagnosis was established as a saccular aneurysm with afferent loop and efferent loop. Patient underwent complete resection of the aneurysm followed by end-to-end anastomosis via median sternotomy. Postoperative pathology was consistent with an atherosclerotic aneurysm filled with thrombus. After surgical operation, hoarseness is still continued.