Thyroglossal duct cyst is the most commonly seen midline congenital neck masses found in children but are not uncommon in adults. The extension of the thyroglossal duct cyst into the larynx is very uncommon. Prelaryngeal thyroglossal duct cyst in a 60 year old man is described in this report. A laryngeal malignancy was suspected because of that cystic mass eroded the thyroid cartilage. The diagnosis was confirmed by fine needle aspiration biopsy. Thyroglossal duct cyst can mimic laryngeal malignancy at old ages patients with laryngeal cystic lesion. Therefore, it should be considered that it is likely to be thyroglossal duct cyst in cystic lesions extended into the larynx.