Abstract: Objective To investigate the value of FNA-Tg in differential diagnosis of suspicious cervical lymph node metastasis in patients with suspicious thyroid cancer. Methods All cases enrolled in this study were selected from patients with thyroid nodular in the Third Affiliated Hospital of Liaoning Medical University from July 2010 to March 2014. A total of 184 patients with suspicious cervical lymph node metastasis were detected by ultrasound (US) and 104 patients were found to have suspicious thyroid cancer, and they all underwent US-guided fine-needle aspiration cytology (FNAC), then their thyroglubin in FNA washout fluid (FNA-Tg) were assayed. The accuracy of FNAC and FNA-Tg in diagnosing the cervical lymph node metastasis was assessed with the pathological diagnosis after surgical resection as the golden reference. Results Compared with the pathological diagnosis, the sensitivity, specificity and accuracy of FNAC and FNA-Tg in diagnosing the cervical lymph node metastasis were 74.0%, 100%, 89.1% and 92.2%, 100%, 96.7%, respectively. The significant difference was detected between FNAC and pathological diagnosis (P=0.03), while no significant difference was found between FNA-Tg and pathological diagnosis (P=0.23). Conclusion As a safe, convenient, reliable and accurate auxiliary method, FNA-Tg can improve the diagnostic accuracy of cervical lymph node metastasis in patients with suspicious thyroid cancer.