Digestive neuro-endocrine tumours have a broad and initially misleading clinical spectrum. Tumours from the duodenopancreatic area should be distinguished from digestive carcinoid tumours. In the first group, insulinomas, gastrinomas, and non-functioning tumours are the most frequent. Insulinoma is responsible for hypoglycaemic symptoms (coma, confusion, seizure, psychiatric disorders) associated with adrenergic response (sweat, tachycardia, palpitations). Gastrinoma is responsible for the Zollinger-Ellison syndrome, which associates peptic ulcers in the oesophagus, stomach, and duodenum without Helicobacter pylori infection, and chronic volumogenic diarrhoea. Non-functioning tumours are recognised fortuitously or at a late stage, when large tumour mass contrasts with often unaltered general condition. Carcinoid tumours are mainly located in the appendix, the rectum, and the small bowel. In the 2 first conditions, the diagnosis is most often made on a resection specimen after uneventful appendectomy or polypectomy; in the latter, the carcinoid syndrome is frequent, combining cutaneous flushing, motor diarrhoea, tricuspid valve insufficiency and bronchospasm.