Congenital thoracic malformations (CTMs) are a heterogeneous group of rare disorders that may involve the airways or lung parenchyma. The authors have focused on the condition that causes the most controversy, namely, congenital cystic adenomatoid malformation (CCAM). The reported incidence is 3.5 and 0.94 per 10,000 live births for CTMs and CCAMs respectively. Ultrasound is the antenatal imaging modality of choice for screening for CCAMs whilst magnetic resonance imaging is complimentary for morphological and volumetric evaluation of the foetal lung. Most CCAMs are detected antenatally with only a small proportion presenting postnatally. Only a few CCAMs cause foetal problems, with foetal hydrops being the best predictor of death. Although many CCAMs regress during pregnancy, most remain detectable postnatally by CT scans. Surgical excision of symptomatic lesions is relatively straightforward, but management of asymptomatic lesions is controversial. Some surgeons adopt a "wait and see" approach operating only on those patients who develop symptoms, but others operate on asymptomatic patients usually within the first year of life. Due to the potential of malignant transformation, children should have long term follow up. There is an urgent need to delineate the natural history of antenatally detected CCAMs to guide future management.