While oesophageal obstacles are responsible for regurgitation or aspiration in neonates and infants, older children present with dysphagia. Before any investigation, a buccopharyngeal infection must first be eliminated clinically. In the absence of fever, the ingestion of a foreign body or caustic substances must be considered, either in an acute context, or in a chronic context related to cicatricial stenosis. Tumour or congenital lesions are less common, whether intrinsic (stenosis, fistulas, duplications), or extrinsic (vascular malformations, mediastinal tumours). Radiological investigation is based on simple techniques: chest X-ray and barium swallow are usually sufficient to establish the aetiological diagnosis.