The clinical course of thyroid carcinoma is delayed but aggressive and lethal in an estimated 11-16% of the patients. Invasion of adjacent structure is infrequent in this tumor. However, invasion of upper aerodigestive tract structures is a source of morbidity and mortality in this disease. Surgical therapy of locally aggressive thyroid carcinoma varies. The choice of surgical procedure often depends on the personal experience of the individual surgeon. We reviewed 39 cases of thyroid carcinoma that invaded the aerodigestive tract, which were treated at the Department of Otolaryngology, College of Medicine, Kyungpook National University Hospital from January 1985 to June 1989. The 39 patients represent 10.8% of the 360 patients with thyroid carcinoma treated at Kyungpook National University Hospital over the same period. Histologic types included papillary(31 patients), follicular(2 patients), giant cell(2 patients) and squamous cell carcinoma(4 patients). The sites of aerodigestive invasion of thyroid carcinoma were cricotracheal junction(34 cases), inferior constrictor muscle (23 cases), cricothyroid muscle(17 cases), trachea(13 cases), esophagus & arch of cricoid cartilage (10 cases, respectively) etc. Radical operation was performed in 13 cases and palliative operation 26 cases. On the basis of the retrospective analysis, I expect that aggressive surgical excision in the form of either complete or near-complete removal of tumor improve the survival rate in patients compared with the survival rate in patient who only have palliative measure to control the airway.