Non-invasive ventilation (NIV) is increasingly being used in preterm infants with the purpose of reducing the risk of adverse pulmonary outcome associated with invasive mechanical ventilation. This review analyzes the evidence from physiologic and clinical studies on the use of NIV in the preterm infant. Physiologic data indicate advantages of NIV with regard to ventilation, gas exchange, breathing effort and thoraco-abdominal distortion. Data from clinical trials have consistently shown facilitation of weaning from mechanical ventilation and potential benefits in infants with RDS and apnoea. Long term improvements in respiratory outcome have also been reported but need to be confirmed in larger trials.