The selection of either conventional mechanical ventilation or HFJV depends on the physical status of the patient,potential physioloic advantages and disadvantages, the requirements of the clinical situation and the capability of providing adequate oxygenation and ventilation. We have experienced that HFJV markedly improved the ventilatory status of a 52-year old male patient with severe respiratory failure due to flail chest and ruptured giant bulla refractory to conventional mechanical ventilatory support.