We review the clinical and pathologic features of seven cases of papillary carcinoma of the thyroid that invaded the trachea and were treated by thyroidectomy, airway resection with reconstructive surgery over an interval of 15 years. We depicted the peculiarity of invasion of well differentiated papillary thyroid carcinoma (PTC) cells is perpendicularly oriented to the tracheal lumen, in between cartilaginous rings, along blood vessels and collagen fibers. Tracheal rings appear non-infiltrated in all histological sections of well differentiated PTC infiltrating the trachea. Similar description of inter-cartilage PTC infiltration into the trachea was first provided by Shin et al. in 1993. Interestingly, our pathological revision support the estimation by Shin et al., though that cartilage rings infiltration did occur in poorly differentiated thyroid cancers with exiguous prognosis.