Congenital lung abnormalities are being detected more frequently at routine high-resolution prenatal ultrasonography. The most commonly encountered anomalies include lung agenesis-hypoplasia complex (pulmonary underdevelopment), congenital pulmonary airway malformations, congenital lobar overinflation, bronchial atresia, bronchogenic cysts, congenital high airway obstruction syndrome, scimitar syndrome, and bronchopulmonary sequestration. Recognizing the antenatal and postnatal imaging features of these abnormalities is necessary for optimal prenatal counseling and appropriate peri- and postnatal management. Supplemental material available at http://radiographics.rsna.org/lookup/suppl/doi:10.1148/rg.306105508/-/DC1. © RSNA, 2010.