Mediastinal bronchial artery aneurysm is rare but potentially life-threatening, and requires prompt treatment to avert rupture with catastrophic results. A 78-year-old man was referred to our hospital with a benign esophageal tumor, which appeared as an extrinsic, extramucosal filling defect on an esophagogram. Chest computed tomography and selective bronchial arteriography led to a definitive diagnosis of mediastinal bronchial artery aneurysm. Aneurysmectomy and closure of the ostia of both the afferent and efferent bronchial arteries was performed via standard posterolateral thoracotomy. Postoperative course was uneventful, and the patient was discharged on the seventh postoperative day.