**Abstract**

Oesophageal atresia (OA) is a congenital anomaly characterised by absence or loss of a segment of the oesophagus. This commonly affects the thoracic portion of the oesophagus, leaving upper and lower oesophageal segments. Loss of the oesophageal luminal continuity leads to impaired in utero swallowing of amniotic fluid as well as postnatal swallowing of saliva and food. Besides the loss of oesophageal continuity, most of the patients tend to have a connection between the trachea and the lower oesophageal segment and a few between the trachea and the upper oesophageal segment, a condition called tracheo-oesophageal fistula (TOF). In view of these, the main principles guiding the definitive surgical management of OA are (1) to disconnect any TOF and (2) to establish a conduit for swallowing, preferably using the native oesophageal segments. This chapter seeks to discuss OA by focusing on the embryology, anatomy and physiology of the oesophagus, stressing on the embryological basis of OA. Other areas to cover include aetiology, pathogenesis, epidemiology, pathologic classification, associated anomalies, pathophysiology, clinical presentation and diagnosis. Further discussion will focus on prognostic classification of patients, management and post-operative complications.

**Keywords:** oesophageal atresia, pathology, associated anomalies, pathophysiology, clinical presentation, diagnosis, pre-operative management, surgical management, outcome, prognosis
