We report a case of intractable chylothorax after right upper lobectomy and nodal dissection via median sternotomy for lung cancer in a 67-year-old man. Lymphangiography (LAG) with lipiodol and sequential computed tomography showed the thoracic duct in the left posterior mediastinum and massive lymphatic leakage in the anterior and middle mediastinum. The Chylous leakage was resolved by LAG with lipiodol. Our findings suggest that variation of the thoracic duct should be evaluated by LAG when intractable chylothorax or chylomediastinum develops after anterior mediastinal surgery.