Chylomediastinum is a rare but serious complication following thoracic procedures. A 70-year-old woman underwent tracheal resection through median sternotomy. Sternal dehiscence and chylous drainage appeared on the second postoperative week. Oral intake was stopped and total parenteral nutrition was started. Drainage stopped after two weeks. The region was ligated with a purse string suture during revision of sternotomy. A minimal lymph leakage was determined on control Tc-99 lymphoscintigraphy, which indicated injury of the thoracic duct. The patient has been problem-free for 9 months.