Chylothorax may be congenital, and occurs due to lymphatic malformations like lymphangioma, lymphangiectasia and atresia of the thoracic duct. Acquired chylothorax occurs due to trauma and post-cardiac surgery. It is also known to be associated with conditions that increase intrathoracic pressure, like superior vena cava thrombosis. As chyle is composed of fats, immune cells and proteins, chylothorax is also associated with metabolic, nutritional and immunological morbidities, apart from respiratory problems. When chylothorax is associated with hydrops, it is a potentially life-threatening condition. Initial treatment is conservative, and includes keeping the baby nil-by-mouth (NBM), and administration of total parenteral nutrition (TPN). Octreotide, a somatostatin analogue, has shown promising results in the treatment of congenital chylothorax. However, when medical management fails, pleurodesis or ligation of thoracic duct is the definitive treatment.