A case is presented of unilateral tension pneumothorax associated with flail chest and pulmonary contusions in a spontaneously ventilating patient after a fall. The tension element was not suspected until chest x ray was available, nor was immediate needle thoracocentesis performed. No morbidity resulted as a consequence. This case highlights the difficulty in deciding whether or not tension pneumothorax is the predominant cause of respiratory distress in a patient with multiple chest injuries. It provides further evidence challenging some of the doctrine on how to treat suspected tension pneumothorax.