In kyphoscoliosis restrictive ventilatory defect occurs. In idiopathic scoliosis vital capacity failure is significantly correlated with Cobb angle, vertebral rotation, and thoracic lordosis. Maximum voluntary ventilation is the most affected measurement. Forced expiratory volume in 1 second is reduced. Residual volume remains longtime normal. Hypoxemia due to decrease of diffusing capacity occurs, with initially reflex hyperventilation hypocapnia, and secondary hypercapnia. Pulmonary hypertension and cor pulmonale is related to hypoventilation and hypoxia. The lung situated on the concave side of the scoliosis curve shows a more functional derangement. Ventilatory pattern consists of low tidal volume and high respiratory rate with increase of ventilatory work. Scoliosis that appears in the earlier stage of the life has the worst respiratory prognosis (before 5 years of age) with impairement of lung and thoracic growth. To stimulate pulmonary and thoracic growth, intermittent ventilatory assistance by pressure preset ventilator should be performed as soon as possible and pursued up to 8 years of age, at least, more if necessity. In over 60 degrees angle idiopathic scoliosis, respiratory failure appears after 40 to 50 years of age. Non invasive ventilatory assistance with preset pressure ventilator by oral way in moderate cases and nocturnal nasal ventilation by volume ventilator or inspiratory assistance ventilator, in the most severe cases are efficient. In very severe and acute respiratory insufficiency (scoliosis over 90 degrees) ventilation by intubation then tractheostomy may be required. Earlier orthopedic management and surgical procedure to correct and stabilize spinal deformities is the best to prevent respiratory insufficiency. For scoliosis below 60 degrees, post operative pulmonary complications are very low, with no requirement of post operative ventilatory support. In very severe respiratory insufficiency treatment of respiratory failure precedes, and follows, orthotic treatment and surgical procedures; it shouldle pursued afterwards.