Cervical thymic cyst is a rare congenital anomaly. Most cases occur in children with asymptomatic neck mass. We encountered a 32-year-old woman who presented with an acute neck mass and respiratory distress. After a series of examinations, including aspira-tion cytology and computed tomography, a hemorrhagic cyst was suspected. The cyst was excised via an external approach. Thymic cyst with hemorrhage was diagnosed by the pathologist. The postoperative course was unremarkable. Although cervical thymic cyst is rare, it should be considered a cause of neck mass. Complete surgical excision is the treatment of choice.