Bronchopulmonary dysplasia (BPD) is a serious lung disease which is increasingly recognised in prematurely born infants in neonatal intensive care units. Little is known about the cause of the disease, the treatment is mainly empirical. Although oxygen is well known to be one of the causal agents for BPD, it is, at the same time, part of its treatment. The neurodevelopmental outcome of infants with BPD is likely to be disturbed, while the lasting treatment often causes problems in the family. Because of the tendency to treat premature infants born after still younger pregnancies, neonatologists are facing a growing number of patients with BPD. In this article the presentation, pathogenesis, diagnostical approach, therapy and the course as well as the follow-up of our patients is discussed.