An unusual tracheal tumor was found in a 50 year old male who was admitted due to mild dyspnea on exertion. Simple chest X-ray showed an abnorma mass shadow in the trachea and computerized chest tomogram revealed a tumor in the mid 1/3 of the trachea obstructing 80% of the lumen. Through a right thoracotomy incision, resection of a 2.5 cm segment of the trachea with end-to-end anastomosis was done and microscopic findings showed many cystic spaces with myxomatous hyalinous stroma. It was diagnosed as a pleomorphic adenoma of the trachea.