Chyloperitoneum is a rare complication of surgical procedures. We report a case of severe chyloperitoneum after abdominothoracic esophageal resection with two-field lymphadenectomy. After diagnosis was established, the lymph leak was located with oral iodine-marked fatty acids (123I-pentadecanoic acid) showing increased activation in the right middle abdomen. Because conservative treatment with total parenteral nutrition showed no decrease in chyle volume, relaparatomy was performed and the lymphatic fistula was successfully treated with suture ligatures. Pathophysiology and different options for localization and treatment of postoperative chyloperitoneum are discussed.