Objective: To investigate the clinical, ultrasonic and pathologic characteristic as well as treatment and outcomes of primary squamous cell carcinoma of thyroid (SCCT). Methods: The clinical presentations, ultrasonic features, pathologic findings and results of comprehensive treatment of 7 primary SCCT patients admitted from January 2010 to December 2015 were retrospectively analyzed. Results: The 7 primary SCCT patients accounted for 0.96% (7/728) of the total number of thyroid cancer patients admitted during the same period, of whom, 3 cases were male and 4 cases were female, with an average age of 62.7 years. All patients had palpable neck mass that was associated with dyspnea in 4 cases, hoarseness in 2 cases and dysphagia in one case. All lesions in ultrasonographic images presented as irregular mixed echogenic solid mass, with thyroid capsule penetration in 5 lesions, microcalcification in 2 lesions and suspicious cervical lymph nodes in 4 lesions. Five patients underwent surgical treatment (thyroidectomy with neck dissection in 2 cases, wide local excision in 2 cases, and palliative resection with prophylactic tracheostomy in one case), and 2 patients underwent coarse needle biopsy only. All cases were confirmed as SCCT by pathology, which was combined with nodular goiter in 3 cases and with papillary thyroid carcinoma in 2 cases, and the immunohisochemical staining for P63 was positive in all cases. Of the 5 patients undergoing surgical treatment, 4 cases had postoperative radiotherapy or radiotherapy plus chemotherapy, and one case did not receive comprehensive therapy; 2 patients undergoing coarse needle biopsy only received radiotherapy or radiotherapy plus chemotherapy. Only one patient who underwent thyroidectomy with neck dissection plus postoperative radiotherapy survived more than one year, and all the remaining patients died within half a year. Conclusion: Primary SCCT is a highly malignant tumor with rapid progress and poor prognosis. Its clinical manifestations and ultrasound imaging have certain characteristics that may help the preoperative diagnosis. Immunohistochemical staining is important for its differential diagnosis, and aggresive comprehensive treatment may improve the prognosis of the patients.