This chapter discusses the most common pulmonary pathologies, including fetal pleural effusions (FPE), pulmonary adenomatoid malformations, and congenital high airway obstruction sequence (CHAOS). It reviews the evidence-based methods of fetal therapy, and available data on fetal and neonatal outcome following antenatal intervention. The appearance of lung septations or solid components suggests an alternate diagnosis, such as congenital pulmonary airway malformation (CPAM) or congenital diaphragmatic hernia (CDH). The most commonly identified prenatal anomalies are congenital cystic adenomatoid malformations (CCAM) and bronchopulmonary sequestration (BPS). CCAM lesions were originally classified based on postnatal histological features: type I macrocystic, type II mixed macrocystic and microcystic, and type III microcystic. CHAOS presents as a syndrome of predicted ultrasound findings, resulting from the various causes of laryngeal or tracheal obstruction in the fetus. The chapter describes three fetal intervention cases with an antenatal diagnosis of CHAOS.