The effectiveness of non-invasive ventilation (NIV) in treating patients with acute respiratory failure (ARF) is showed by its ability to diminish the recurrence to endotracheal intubation (ETI), the occurrence of ETI-associated lung infections as well as related mortality. A specific issue is the outcome of NIV in patients referring to Emergency Department for ARF who receive a do-not-intubate (DNI) order because of too critical conditions or advanced age. Recent data show that elderly patients (mean age 81 years) with ARF who have a DNI order can be successfully treated by NIV, as demonstrated by a survival rate of 83%. The positive outcome was confirmed by a subsequent 3-year observation, that demonstrated an overall survival rate of 54%. These findings clearly suggest to treat by NIV elderly patients also in presence of a DNI order.