The association of squamous cell carcinoma of the larynx with thyroid papillary carcinoma is an unusual finding. From 2004 to 2011, approximately 250 patients underwent laryngectomies due to squamous cell carcinoma of the larynx at the Otolaryngology Department of Khalili Hospital, affiliated with Shiraz University of Medical Sciences, Shiraz, Iran. In three patients, synchronous occurrence of squamous cell carcinoma and thyroid papillary carcinoma was found. Histopathologic study of the lymph nodes revealed metastatic papillary thyroid carcinoma in one case. We report three cases of thyroid papillary carcinoma incidentally found on histological examinations of resected thyroid lobes, as a procedure required for treatment of head and neck squamous cell carcinoma. In comparison, laryngeal squamous cell carcinoma needs more aggressive treatment than well-differentiated thyroid carcinoma. The prevalence of thyroid papillary carcinoma, as an incidental finding in our study was 0.01%. Therefore, preoperative evaluation of the thyroid gland by ultrasonog- raphy and fine needle aspiration biopsy of suspicious lesions is recommended in patients who are candidates for open laryngectomy.