29 patients with chronic respiratory failure due to neuromuscular deficits and restrictive chest wall disorders were treated with nocturnal ventilation via nasal mask at home for at least one year. Home ventilation was provided by a volume cycled positive pressure ventilator attached to a nasal mask which was made to measure by modelling silicon paste onto the patient's face. This method was well tolerated. The majority of the symptoms of hypoventilation rapidly disappeared with nocturnal ventilation and the daytime PaO2 and PaCO2 improved significantly allowing the patients to perform more daily activities. Nocturnal nasal ventilation is efficient but needs strict supervision. The nasal mask can replace or postpone tracheostomy which, if needed, remains a possible and efficient method.