The techniques of non-invasive ventilation hade reappeared in force as an assortment of therapeutic techniques since the end of the 1980's. At the same time there was a transient renewed interest in perithoracic ventilation favouring the use of new methods of connection to the patient (e.g. poncho). The principal feature has been the use of intermittent positive pressure ventilation by the nasal route, which rapidly became essential for home therapy in patients with chronic restrictive respiratory failure notably in chose secondary to thoracic deformation and to neuromuscular pathology. The concept of resting the respiratory muscles has been the basis for techniques of ventilatory assistance and in part the nasal route has now replaced home ventilation using a tracheotomy. Also in certain types of acute respiratory failure, nasal ventilation widely prefered over endotracheal ventilation.