Chylothorax is characterized by a milky pleural effusion that results from the injury to the thoracic duct, causing leakage of chyle into the pleural space. Its diagnosis relies primarily, on the determination of triglycerides and/or the identification of chylomicrons in the pleural fluid. The most common causes are traumatic, mainly after surgery. Among non-traumatic causes, tumors are the most frequent (like lymphomas). Conservative treatment is based on pleural drainage with a low fat diet and appropriate etiological approach. In case of failure, occlusion of the thoracic lymph duct should be considered, either by a surgical approach or interventional radiology.