Chylothorax is an uncommon disease where fatty fluid accumulates within the chest cavity. Conservative management, including repeated thoracentesis or pleurodesis, seems to be suitable to most cases. Herein, we present a case of efficacious pleurodesis by intrapleural injection of Sapylin, a streptococcus preparation, for the treatment of chylothorax. A 52-year-old non-smoking female farmer was diagnosed as idiopathic chylothorax after we ruled out possible causes including chest trauma,lymphoma, lung cancer, filariasis, tuberculosis, and etc. Two-time intra-thoracic injection of 3 Klinische Einheit (KE) Sapylin achieved rapid and effective control of chylothorax with no severe side effects. Sapylin may facilitate pleurodesis by producing a strong inflammatory response.