Chylothorax is an uncommon but potentially life-threatening complication of esophagectomy. A 72-year-old man underwent thoracoscopy-assisted subtotal esophagectomy and reconstruction with a gastric tube, through a retrosternal route, after preoperative chemoradiotherapy. Chylothorax was detected after starting enteral feeding on postoperative day (POD) 7. Despite conservative therapy such as fasting, total parenteral nutrition, and octreotide administration, massive fluid drainage continued. On POD 19, lymphoscintigraphy with (99m)Tc-diethylenetriamine pentaacetic acid-human serum albumin (HSA-D) was performed and the site of leakage was detected at the level of the fourth thoracic vertebra. On POD 23, the thoracic duct was ligated, following which the volume of chylothorax decreased. Lymphoscintigraphy 12 days after the reoperation showed no leakage from the thoracic duct. We recommend lymphoscintigraphy with (99m)Tc-HSA-D for locating the chyle leakage site and helping decide about the operative indication.