Airway liquid content and insufficient absorptive airway ion transport at birth are potentially important factors in the development and severity of neonatal respiratory disease. The role of deficient absorptive airway ion transport in the development of chronic lung disease of prematurity is unknown. Additionally, lung inflammatory mediators modulate airway ion transport. Their effect on preterm lung ion transport and absorptive capacity is not established. We performed serial nasal potential difference studies and broncho-alveolar lavage in preterm infants born less than 30 wk postmenstrual age over the first four postnatal weeks. Our study aims were to: 1) compare nasal potential difference between preterm infants developing chronic lung disease and babies of similar gestation who do not; and 2) examine for an association between airway inflammation and ion transport parameters. We found that potential difference across the nasal epithelium increased with gestation, remained low and unchanged in infants developing chronic lung disease over the first four postnatal weeks, was significantly lower at four weeks in chronic lung disease infants, and was not associated with lower airway inflammation at any time point. We conclude that infants with chronic lung disease postnatally have a persistently reduced absorptive airway ion transport capacity.