The present study aims to report the first case of chronic neck sinus post-thyroidectomy caused by oxidized regenerated cellulose (ORC). A 55-year-old female patient underwent a total thyroidectomy operation. Three months after the surgery, the patient presented with persistent purulent discharge and sinus at the site of the drain. A CT scan of the neck showed a fistula tract, deep-neck fluid collection, and bilateral paratracheal high-density lesions at the thyroid bed, suggesting infected foreign bodies. The patient underwent surgery, during which the mesh of the ORC was found nonresorbed at the paratracheal space. The treatment involved neck exploration with the removal of all retained material and excision of the sinus tract. The patient had a favorable outcome following the surgical excision of the sinus tract and the removal of retained hemostatic materials. Further research is needed to explore the risk factors and preventive measures for neck sinus formation to enhance the safety and outcomes of thyroidectomy.