Objective: The increased survival of preterm infants poses the challenge of dealing with a wide range of chronic pulmonary diseases, including bronchopulmonary dysplasia, Wilson-Mikity syndrome and recurrent wheezing. This article reviews the pulmonary clinical and functional prognosis of preterm newborns in infancy and adolescence.Source of data: MEDLINE search for articles published between 1970 and 2004 that focused on lung growth and function of preterm infants, besides a clinical follow-up of this group.Summary of the findings: Prenatal and postnatal events, such as placental insufficiency, tobacco exposure, infections, oxygen and mechanical ventilation, have an important effect on lung development and can lead to chronic lung diseases, of which bronchopulmonary dysplasia is the most severe complication. However, significant loss of lung function occurs in preterm infants who do not fulfill the criteria for bronchopulmonary dysplasia, and even in those who did not have significant respiratory disease during the neonatal period. The impact of prematurity on the respiratory system of these patients is usually underestimated. Clinically, preterm infants have an increased incidence of pneumonia and bronchiolitis, hospital readmissions due to respiratory diseases, chronic cough and wheezing and bronchial hyperresponsiveness. In adolescence, there is a tendency for normalization of the lung function, but they persist with reduced flows, lower exercise tolerance and bronchial hyperresponsiveness.Conclusions: Prematurity, the events that cause it and the interventions that follow it permanently change the development of the respiratory system. Studies are necessary to clarify the effect of each of these perinatal insults on the development of the respiratory system. J Pediatr (Rio J). 2005;81(1 Suppl):S79-S88: Premature infant, bronchopulmonary dysplasia, spirometry, breath tests, hyaline membrane disease.