Chylothorax is a lymphatic effusion of chylous in the pleural space due to thoracic duct obstruction or injury. The most frequent aetiology is cancer; it is also related to chest trauma and iatrogenic. We describe the case of bilateral chylothorax in a 76-year-old woman, right predominant, during the post-operational phase of gastric surgery. This presented itself with respiratory insufficiency and tachycardia without initial haemodynamic compromise. It presented a favourable evolution after conservative treatment, cessation of oral intake and TPN and chest tube during 10 to 14 days.