In this preliminary study we assessed the feasibility and efficiency of non-invasive ventilation (NIV) with a buccal mask (NIV-BM), not fitted with a mouthpiece, in surgical patients in acute respiratory failure whose lungs could not be ventilated with a face mask. In the eight patients enrolled in the study, NIV-BM increased tidal volume, decreased respiratory rate and improved PaO2. In two patients the trachea had to be intubated and one of them died of septic shock. NIV-BM can act as a valuable alternative in surgical patients in acute respiratory failure in whom a face mask cannot be used because of leaks or bad tolerance.