Mechanical ventilation is associated with significant short- and long-term morbidity in small preterm infants. Continuous positive airway pressure applied through nasal prongs is an effective, less-invasive method to improve gas exchange and reduce apnea in these infants. A large number of studies have evaluated the possibility of reducing the need or duration of mechanical ventilation by early use of nasal continuous positive airway pressure shortly after birth and by applying it after extubation. Although results of these trials have not been consistent, most of the evidence suggests that nasal continuous positive airway pressure is a viable alternative to mechanical ventilation in many preterm infants and that its use after extubation contributes to maintain better lung function and reduces apnea. Despite this, there is no evidence that these beneficial short-term effects translate into lower rates of long-term morbidity such as bronchopulmonary dysplasia and neurologic sequelae or mortality rates.