Pulmonary air leaks are usually complications of mechanical ventilation, although they can occur spontaneously. The reported incidence varies from 1% in term infants to 20% in preterm infants. The incidence has decreased in recent years. Ventilatory manoeuvres which increase mean airway pressure are associated with increased air leaks. Use of higher ventilatory rates, shorter inspiratory times and surfactant are known to reduce the incidence. Pulmonary interstitial emphysema presents as a slow deterioration of the infant during ventilation. Pneumothorax is usually associated with sudden deterioration. The diagnosis of a tension pneumothorax is clinical and emergency management should not be delayed for a confirmatory X-ray. A ventilatory strategy allowing for permissive hypercapnia with lowest possible pressures, shorter inspiratory times and higher ventilatory rates may aid in the management of pulmonary air leaks. High frequency ventilation may help when conventional ventilation fails. Sedation and paralysis may be helpful when the infant fails to synchronize with the ventilator. Pulmonary air leaks are associated with increased mortality and morbidity and a higher incidence of intraventricular haemorrhages.