Cases of bronchial artery aneurysms (BAAs) are rare; to the best of our knowledge, only 50 cases have been reported in the literature to date. BAAs require optimal treatment due to the possibility of life-threatening hemorrhaging if the aneurysm was to rupture. BAAs are usually treated by surgical resection of the aneurysmal artery. However, when the patient is unstable due to massive or recurrent hemoptysis, a bronchial artery embolization is a useful alternative treatment method. We report a case of a giant mediastinal bronchial artery aneurysm that was treated by coil embolization.