With the advent of improved antenatal imaging over the past 10 years, the diagnosis, assessment and management of congenital cystic lung abnormalities have changed. These were once considered the exclusive domain of the surgeon, who had the authority to operate on all congenital cystic lung abnormalities regardless of size or clinical signs in order to avoid the risk of cancer and improve lung growth in even asymptomatic infants. Clinicians are reconsidering this approach in the light of an appreciation of the spontaneous improvement and possible resolution that occurs over months to years with many of these lesions. The risks of subsequent cancer are poorly understood and probably overstated, whereas the magnitude of compensatory lung growth is poorly defined in the majority of children with small unilateral congenital cystic abnormalities. The evolution of regional, national and ideally international databases will provide much-needed longitudinal data to better inform clinicians of the optimal way in which to manage these children.