Thirty patients with tracheal invasion of differentiated thyroid cancer underwent partial resection of the tracheal wall between 1978 and 1996 at National Cancer Center Hospital. In most cases, the defect in the tracheal wall was reconstructed secondarily using a local flap. This method was easy in comparison with end-to-end anastomosis of the trachea following circumferential resection of the wall. Partial resection of the tracheal wall proved to be a effective treatment for thyroid cancer invasion of the tracheal, because of low incidence of local recurrence. When the defect of the tracheal wall was too large to be reconstructed using a local flap, hydroxylapatite was employed and good results were obtained.