The development of multiple primary tumors is a problem leading to the treatment of patients diagnosed with gingival squamous cell carcinoma (SCC). The occurrence of multiple primary cancers in patients with SCC of the head and neck is uncommon. Thyroid carcinomas have been found incidentally in the cervical lymph nodes after histopathologic examination. A 72-year-old male with SCC of the lower gingiva at the clinical stage T2N0M0 was treated with partial mandibulectomy and selective neck dissection. Histopathologic examination showed the foci of papillary thyroid carcinoma metastasis. The patient subsequently underwent total thyroidectomy. We report a case of papillary thyroid carcinoma associated with SCC of the oral gingiva along with a review of literatures.