Thoracic duct cysts are uncommon entities that most commonly occur in the abdominal and thoracic segments of the thoracic duct; the rarest reported location is the cervical segment. The first case of a cervical thoracic duct cyst was reported in 1964,1 and a review of the literature that was published in 1999 identified only 10 such cases.2 We describe a patient with a thoracic duct cyst, review the relevant literature, and discuss the characteristics, treatment, and diagnosis of these lesions.