Aim: To investigate the expression of protein kinase $CK2{alpha}$ ($CK2{alpha}$) in human thyroid disease and its relationship with thyroid cancer metastasis. Materials and Methods: Using immunohistochemistry we measured the expression of $CK2{alpha}$ in 76 benign and malignant human thyroid cancer tissues, including 10 pairs of papillary carcinoma tissues with or without lymph node cancerous metastasis and similarly 10 pairs of lymph nodes. Results: The expression of $CK2{alpha}$ was found to be higher in thyroid carcinoma cases (papillary carcinoma, follicular carcinoma, anaplastic carcinoma and medullary carcinoma) than in ones such as chronic lymphocytic thyroiditis, nodular goiter and adenoma. These findings were also confirmed by RT-PCR and Western blotting. More strikingly, elevated expression of $CK2{alpha}$ in thyroid papillary carcinoma tissues was not only significantly associated with lymph node cancerous metastasis and clinical stage of thyroid cancers; but also correlated with epithelial-mesenchymal transition (EMT) and high tenascin C (TNC) expression. In addition, EMT and high TNC expression in thyroid carcinoma tissues was significantly associated with lymph node cancerous metastasis. Conclusions: Elevated expression of nuclear $CK2{alpha}$ is a poor prognosis indicator in lymph node cancerous metastasis of human thyroid cancers.