In this case report, we introduce on two unusual cases in which Non-invasive ventilation (NIV) was applied to elderly patients with respiratory failures. The first case needed ventilatory support because of acute respiratory failure. Although patient's situation was not “end-of-life”, but “curative”, surrogates did not agree to intubate since the patient had previously declared “do not intubate (DNI)”. The use of NIV allowed the patient to overcome the disease. The latter case, we introduce a patient with underlying tuberculosis-destroyed lung who showed dyspnea and chronic hypercapnia respiratory failure after influenza infection. This patient could manage hypercapnia and dyspnea through using NIV, and finally, she could wean the ventilator. Like our cases, if NIV can be used properly, treatment choices can be significantly expanded for patients with acute respiratory failure. We expected that these cases would widen the range of NIV use in elderly patients