Background: Anaplastic thyroid carcinoma (ATC) is a rare malignant tumor with strong invasiveness and lethality, which is common in elderly women with short survival. This paper introduces a case of multiple metastatic thyroid carcinoma in order to provide reference for early diagnosis, prevention and later treatment. Case presentation: An 84-year-old woman was admitted to hospital with "pharynx pain for 10 days". Thyroid ultrasonography showed solid nodules on the right side of the thyroid gland (TI-RADS4A). Ultrasound-guided FNA was recommended. There are multiple abnormal lymph node echoes in both sides of the neck, so puncture biopsy is recommended. CT shows that the right lobe of thyroid occupies space, so puncture biopsy and MRI examination are recommended; multiple lesions in both lungs are considered, and metastatic tumors are considered; thyroid biopsy is performed by ultrasound-guided percutaneous exploration and fine needle aspiration biopsy. Pathological results show that thyroid malignant tumor is considered as undifferentiated thyroid carcinoma. Targeted therapy was used in the treatment plan. During the follow-up three months after discharge, the patient's family informed the patient that she had died. Conclusions: This case report shows that early use of FNA can reduce the rate of missed diagnosis of ATC and provide accurate guidance for follow-up treatment. As far as we know, this is a rare case report of multiple metastases of this disease.