Congenital narrowing of the nasal airway at the posterior choanae is an uncommon condition in pediatric patients, which can be uni-or bilateral. The presentation of bilateral choanal atresia is a neonatal airway emergency, requiring prompt treatment. The repair of unilateral choanal atresia is often an elective surgical procedure of early childhood, for which a variety of techniques have been described.Choanal atresia occurs as an isolated abnormality, or as part of a syndrome, most commonly CHARGE syndrome. Choanal atresia, and associated abnormalities such as abnormal semicircular canals and cranial nerve abnormalities, are integral part of the diagnosis of CHARGE syndrome. There is increasing understanding of the biology of choanal atresia, and aetiological risk factors are starting to become apparent. This review will discuss the diagnosis, aetiology, and surgical treatment of choanal atresia.