Primary Squamous Carcinoma of Thyroid(PSCT) is a rare but distinct clinicopathological disease. Due to the paucity, optimal intervention strategy has not been established yet. PSCT was once viewed as radioresistant. Here we present a rare case of PSCT in which postoperative radiotherapy was effective for local control and maintenance of progression free survival (PFS) of more than 10 months after R2 resection. Our case will help to identify the role of adjuvant radiotherapy in the treatment of PSCT and extend our understanding of this rare thyroid carcinoma.