Chylothorax is a rare postoperative complication of general surgery. It has never been reported to occur after subtotal gastrectomy and vagotomy. We described a 66-year-old man who developed left chylothorax resulting from subtotal gastrectomy and vagotomy. Conservative treatment was tried first. Then, surgical intervention through right-sided videoassisted thoracoscopic surgery with clipping of the right thoracic duct was performed, but failed. Finally, left thoracotomy with ligation of the branch of the thoracic duct at the supradiaphragmatic region resolved the left chylothorax.