There have been significant strides made over the last two decades in the understanding of the natural history and pathophysiology of fetal thoracic lesions. Largely as a result of advances in prenatal ultrasound we are not only able to offer a tentative diagnosis of these lesions and advise parents about the prognosis but in selected centres offer the possibility of intervention for the most severely affected fetuses. Large gaps do remain in the current state of knowledge, in particular in the inability to predict pulmonary hypoplasia. Fetal surgery for lesions such as congenital cystic adenomatous malformation (CCAM) and pulmonary sequestration sequence (PSS) is still restricted to a very few centres and is reserved for those fetuses with hydrops where there is an extremely poor prognosis. Selection criteria for intervention have been refined over the last decade. Postnatal imaging studies, particularly computed tomography (CT) are essential in the evaluation of these lesions prior to surgical resection.