Summary Solitary fibrous tumors(SFT) of the thyroid gland are rarely reported,especially metastases from a malignant solitary fibrous tumor(MSFT) of lung.We herein present a 35 year old man with history of SFT of lung and a 6 month history of rapidly enlarging thyroid masses.The CT showed masses in the left thyroid lobe.We performed thyroid lobectomy plus central compartment neck dissection.Immunohistochemically,Bcl2,Vim and CD99 were positive,while CK,CD34,EMA,TG,P53 and S100 were negative.Combined with patient medical history and pathological diagnosis,it confirmed that MSFT of the lung metastatic to the thyroid gland.within a period of 7 months of follow up,no reoccurrence was found so far.