Chylous drainage from a stab wound to the neck. A 24-year-old man was assaulted and sustained a stab wound to the left lower neck. When he arrived at the emergency department, he was hemodynamically stable. Although the wound had penetrated the platysma, on initial evaluation the patient did not appear to have sustained significant injury. Closer examination of the wound revealed chylous drainage, indicating injury to the cervical portion of the thoracic duct. The patient was taken to the operating room for exploration of the wound, during which an injury to the left internal jugular vein was identified and repaired. The thoracic duct, which had been severed, was ligated. The remainder of the patient's hospital course was unremarkable. The consistent association between penetrating injury to the cervical portion of the thoracic duct and injury to neighboring vascular structures is discussed. 