Injury to the thoracic duct causing a chyle leak is the most common complication following a left neck dissection, carrying a high degree of morbidity when it occurs. There are no diagnostics routinely used to assist with thoracic duct identification intra-operatively. Lymphangiography using Indocyanine Green (ICG) has previously been described; however there have been no reports of its use in mapping the thoracic duct during neck dissection. In 8 patients undergoing left modified radical neck dissection for either thyroid cancer or melanoma, ICG (2.5 mg/mL) 2 mL was injected subcutaneously on the dorsum of the left foot 5-15 minutes before imaging. Intraoperative imaging of the neck was performed with a hand-held Near InfraRed (NIR) camera (Hamamatsu, PDE-Neo). In 7 patients the thoracic duct was visualized using the NIR camera including 1 patient in which intra-operative injury was identified. The thoracic duct was ligated and the patient had no chylous fistula post-operatively. Time from injection to identification of the thoracic duct was variable at 15 to 90 minutes. Imaging was optimized by positioning the camera at the angle of the mandible and pointing in a caudal direction into the space below the clavicle. This is the first description of using ICG lymphangiography for identification of the thoracic duct in the neck. Identification with ICG is technically feasible, simple to perform with NIR imaging, and safe. This technique may become an important adjunct for the surgeon to facilitate identification of the thoracic duct and recognize intra-operative injury.