Primary squamous cell carcinoma of the thyroid is rare, presenting much less than one percent of all primary thyroid malignancies. Most cases have been reported in elderly patients with a history of goiter. It is necessary to differentiate between primary squamous cell carcinoma and secondary involvement from other sites. Secondary involvement of the thyroid may be more amenable to palliation or cure. The treatment of choice in primary squamous cell carcinoma is radical surgery in resectable cases, but the squamous cell carcinoma behaves aggressively and carries a uniformly poor prognosis regardless of the treatment. We had an experience of a primary squamous cell carcinoma of the thyroid in two elderly patients. These patients presented a typical feature of a primary squamous cell carcinoma of the thyroid, which has been rarely reported in Korea.