Abstract: Objective To analyze the etiology, route of infection, and treatment of a thyroid abscess caused by acute tonsillitis, which finally resulted in parapharyngeal space infection. Methods According to CT results, the site was incised laterally to reveal the neck space thoroughly. After that, the abscess was drained and rinsed carefully. Results The patients temperature lowered day by day, and the patient recovered after 10 days. Conclusion B ultrasound combined with enhanced CT is an effective means for the identification of neck cyst and abscess. Puncture pathological examination is the gold standard for diagnosis. If oral or maxillofacial infections are concurrent with thyroid cyst, special attention should be paid to abscess formation. Lateral neck incision, adequate irrigation and drainage are effective means to treat pharyngeal space abscess.

Key words: Thyroid abscess, Infection of parapharyngeal space, Tonsillitis