In the course of chronic respiratory insufficiency, acute episodes often require the use of mechanical ventilation. Failure of weaning, or worsening of alveolar hypoventilation, results in long term ventilatory assistance with the need of overall care of the patient. The pneumologist has a key role in the choice of indications, devices and mode of home mechanical ventilation. Thanks to the non-invasive ventilation with a facial or nasal mask, tracheostomy is less often needed. Respiratory failure due to lung restriction is the best indication of mechanical ventilation. The results in COPD are questionable. Whatever to the technique of ventilation and the underlying disease, the pneumologist has to ascertain the steady state of the medical condition, patient and family education, and social situation, all factors to be taken into account before the patient can be discharged. Knowing the specific needs in these patients'care, the pneumologist plays a key role at each stage of home return and follow-up. He co-ordinates the different aspects of pneumological care, like rehabilitation and acute episodes treatment. The overall care of the patients should be improved by the development of health networks in the field of chronic respiratory insufficiency.