<p>Noninvasive ventilation (NIV) is an established method for respiratory support or ventilation of patients without the use of an invasive airway access device. The use of NIV has proven effective in emergency prehospital medical services and also in acute and emergency medicine for treating acute respiratory insufficiency, in cases such as exacerbation of a&#xa0;chronic obstructive pulmonary disease (COPD), cardiac pulmonary edema or severe pneumonia. Another indication is the preoxygenation before endotracheal intubation. If the correct indications are present and when correctly applied, NIV can reduce the probability for endotracheal intubation, lower patient mortality and shorten the hospital stay; however, there are important contraindications that must be considered. This article provides reliable knowledge on the practical application of NIV treatment in emergency medicine.</p>