Lung aeration is the most critical task newborns must accomplish after birth. Almost all extremely preterm infants require respiratory support during this process, but the best method to promote lung aeration in preterm infants is unknown. The current standard practice is intermittent positive pressure ventilation with positive end-expiratory pressure. Sustained inflation is a promising alternative strategy for lung liquid clearance and aeration. Here we review the physiologic rationale for sustained inflation and the available clinical evidence for sustained inflation in preterm infants.