A 3.5 year old male castrated domestic shorthair was presented to Cornell University Hospital for Animals Emergency Service for evaluation of respiratory distress. His primary care veterinarian diagnosed an idiopathic chylothorax via thoracocentesis. Upon referral to Cornell University Hospital for Animals, 170 mL of chylous effusion was drained from the thoracic cavity, and a lymphangiography study was performed. Surgical correction was elected and included thoracic duct ligation, cisterna chyli ablation, pericardectomy, and a pleural port placement. The cat recovered uneventfully from surgery, did well at home, and was transferred to an Internal Medicine specialist for continued post-operative care and management of the pleural port.