Chylothorax is the accumulation of fat-containing lymphatic fluid within the pleural cavity. It represents a rare but clinically significant cause of a pleural effusion. The condition can occur due to obstruction or injury of the thoracic duct attributable to various etiologies, including traumatic injury, malignancy, congenital anomalies, infection, and idiopathic causes. The underlying pathophysiology involves the leakage of lipid-rich chyle into the pleural space as it is transported through the lymphatic system before entering the systemic circulation. Clinically, chylothorax presents with symptoms such as dyspnea, chest discomfort, and indications of nutritional or immunological compromise resulting from the loss of proteins, fats, and lymphocytes. The diagnosis can be confirmed with pleural fluid analysis, which reveals a characteristic milky appearance, elevated triglyceride levels, and the presence of chylomicrons. Advanced imaging techniques and lymphangiography may reveal the underlying etiology and identify the precise site of the leak. Management includes dietary restrictions aimed at reducing chyle production and the drainage of pleural fluid, as well as pharmacological interventions and definitive surgical or interventional radiological procedures for cases that are unresponsive to conservative therapy. Although traumatic and iatrogenic chylothorax often resolve with appropriate treatment, malignant and congenital etiologies have variable outcomes influenced by the underlying pathology. Advances in diagnostic techniques and therapeutic modalities have improved the prognosis overall.