Mechanical ventilation is a procedure that enables artificial support to gas exchange in cases when spontaneous breathing cannot provide adequate minute ventilation. It is performed using a special device – the ventilator. Ventilators mainly used today are microprocessor-controlled positive pressure ventilators. The main objectives of mechanical ventilatory support are preservation of alveolar ventilation and arterial oxygenation, maintenance of adequate lung volumes and reduction in the work of breathing, while trying to maximally decrease the possibility of iatrogenic lung injury. Standard criteria for instituting mechanical ventilatory support include apnea, respiratory failure, GCS ≤ 8 and severe burns of the face and neck with predictable airway edema. There are several classifications of mechanical ventilatory support – according to the way the inspiratory force is created (negative or positive pressure ventilation); according to the presence of an artificial airway (invasive versus non-invasive) and according to the work of breathing (full or partial ventilatory support). Each respiratory cycle accomplished by the ventilator is divided into four phases and controlled by the phase and control variables. Depending on the choice of the main control variable, ventilators are commonly described as volume controlled or pressure controlled. The combination of the breath type (which can be mandatory or spontaneous) and the set of variables during mechanical ventilation determines the mode of ventilation. Selection of a particular mode depends mainly on indication and clinician preference. Because the duration of mechanical ventilation is in correlation with a higher risk of complications, the length of time spent in hospital and the overall patient outcome, it is important to follow the evidence-based guidelines for ventilator weaning and precisely establish the moment when the patient meets the criteria for ventilator discontinuation.