A 46-year-old woman underwent a right thyroidectomy with left neck dissection under general anesthesia. The operation was performed successfully for over the course of 3 hours 30 minutes. After extubation, the patient was transferred to post-anesthetic care unit (PACU). After 10 minutes, dyspnea, chest discomfort, desaturation was suddenly occurred. Intubation was performed in PACU. The emergency chest X-ray revealed a right pneumothorax, and the patient was treated by chest tube insertion. The patient was improved and was discharged uneventfully from hospital 8 days later.