A bronchogenic cyst is congenital malformation of the foregut which was generally encountered within the mediastinum and detected in pediatric patients with symptoms of infection or compression on vital structures. They are rarely detected in adult population as a neck mass. We have recently experienced one case of bronchogenic cyst as a parathyroid mass in a 50-year-old female. It was incidentally detected by routine neck ultrasonography and interpreted as a parathyroid cyst with hemorrhage preoperatively, but confirmed as a bronchogenic cyst at pathologic examination. We report this case with review of literatures.