Objective To analyze and summarize clinical characteristics, diagnostic method, choice of treatment, and prognosis of metastatic lung cancer to thyroid gland. Method The clinical materials of the 15 patients presenting with secondary thyroid cancer were analyzed retrospectively. Results There were 10 females and 5 males in the 15 patients, with the female to male ratio of 2 : 1. The age ranged from 36 to 79 years old with an average 59 years old. The diagnoses of 12 cases were made by the surgery or the fine needle aspiration biopsy (FNAB), 3 cases by the clinic. The interval from the diagnosis of the primary tumor to the thyroid metastasis varied from 0 month to 21 months with an average 4 months. Three patients received the thyroidectomy, 5 patients received the chemotherapy or chemoradiotherapy, and 7 patients gave up the treatment. The average survival time was 10 months. Conclusions Metastatic lung cancer to thyroid gland is rare, and FNAB is a useful tool for diagnosis. Thyroidectomy may not be recommended because of poor prognosis.