Adequate training for the insertion of chest drains in a trauma setting reduces the occurrence of procedure-related complications. Prophylactic antibiotics reduce the risk of infectious complications and empyema. For drainage of a traumatic pneumo- or haemothorax a large drain (28-36 French) is advised. The preferential insertion site is the 5th intercostal space in the midaxillary line. Drainage systems consist of a collection bottle, water seal and a suction control. Suction applied at 15-20 cm H2O is recommended for adequate drainage. Conversion to thoracotomy is determined by the drain production. Occult air leaks before removal of the drain can be detected by a temporary water seal or by clamping the drain followed by a chest X-ray. Removal of a chest drain at end-inspiration is as secure as end-expiration. Attention must be paid to potential complications of chest drains.