Chylous fistula is a rare complication occurring after radical neck dissection. Previous reports on neck dissection described an incidence of about 1% to 2%. We report a case of chylous fistula that occurred after radical neck dissection for squamous cell carcinoma of left lower gingiva and mandible in a 52-year-old man. We successfully managed the fistula by the following conservative measures : bed rest with head elevation, continuation of closed suction drainage, and dietary management to decrease the rate of chyle formation.