AbstractChylothorax, an uncommon cause of pleural effusion, results from the accumulation of lymph in the pleural space due to damage or obstruction of the thoracic duct. Chylothorax can be due to several aetiologies, many of which are rare, and it is often a diagnostic challenge to identify the cause. This case report refers to a patient with rapid recurrent episodes of bilateral pleural chylothorax due to damage of the thoracic duct after external electrical cardioversion treatment. The diagnosis took place by the method of exclusion, when all known causes of chylothorax, both non‐traumatic and traumatic, were ruled out. A review of the literature on chylothorax was performed using PubMed to assess the different aetiologies, investigations, and treatments usually performed. Chylothorax is usually secondary to malignancy, trauma, congenital diseases, and infections. However, even non‐invasive thoracic procedures, such as the one described in our case report, can be the cause.