Most tracheal tumors are malignant, and benign neoplasms are extremely rare. We herein report the case of a 60-year-old woman with a tracheal lipoma obstructing the right main bronchus in whom a preoperative diagnosis was not able to be established. Thus, a thoracotomy was performed followed by complete resection of the tumor including two rings of the tracheal wall. Pathologic examination confirmed that the tumor was a lipoma covered with tracheal epithelium, extending between the cartilage into the outer layer of the trachea.