A 69-year-old female complained of husky voice and dyspnea. Bronchofiberscopic examination revealed a tumor at the left side of the trachea, which obstructed approximately 80% of the tracheal lumen. Benign pleomorphic adenoma was diagnosed by biopsy. The tumor was removed by circumferenctial resection of the trachea with partial sternotomy adding to the 3 th intercostal transverse resection. Historical finding of the resected specimen revealed a carcinoma arising from benign pleomorphic adenoma of the trachea and residue of malignancy at the margin of the trachea and esophagus. Additional radiotherapy was performed (60 Gy). The postoperative course was uneventful for 4 months and one year.