Noninvasive ventilation (NIV) is one of the cornerstone treatments for acute respiratory failure. NIV can be used in two different modalities based on the underlying pathology and patient characteristics: continuous positive airway pressure (CPAP) that involves the application of continuous positive pressure throughout the entire respiratory cycle and bilevel positive airway pressure (BiPAP) that includes both the application of continuous positive pressure and a support pressure (inspiratory positive airway pressure, IPAP). Noninvasive ventilation, especially the application of positive end-expiratory pressure (PEEP), has hemodynamic and respiratory effects. About hemodynamic effect, PEEP reduces ventricular preload and afterload without impact on myocardial contractility. The reduction of ventricular afterload consequently reduces myocardial oxygen consumption and increases cardiac output. NIV also improves respiratory function, increasing oxygenation and decreasing both partial pressure of carbon dioxide (pCO2) and respiratory work. One of the clinical conditions in which NIV is most commonly used is acute cardiogenic pulmonary oedema. In the setting of acute cardiogenic pulmonary edema, acute coronary syndrome (ACS) represents one of the most frequent causes. Since the late 1990s, several conflicting studies have been published about the use of noninvasive ventilation in the treatment of acute myocardial infarction (AMI) complicated by respiratory failure. NIV has shown a faster improvement in symptoms and gas exchange, as well as a reduction in the need for endotracheal intubation. Subsequently, some studies reported an increase in the incidence of acute myocardial infarction with the use of NIV, starting the decline of its use in emergency setting. Only after the 2000s, thanks to some studies and meta-analyses, both the efficacy (reduction in the need for endotracheal intubation and mortality) and safety (denied the risk of myocardial infarction) of non-invasive mechanical ventilation have been demonstrated, especially for the treatment of AMI complicated by respiratory failure.