AbstractThe emergency management of patients presenting with the Zollinger‐Ellison syndrome (ZES) consists of medical measures to control acid‐pepsin hypersecretion; emergency surgery should be confined to urgent complications of ulceration or tumor growth and spread. Operation for ulcer complications should be restricted to conventional surgical procedures with biopsy of suspicious lesions. Emergency total gastrectomy or resection of pancreas and duodenum is contraindicated. Once the emergency has been controlled, the diagnosis of ZES can be confirmed by basal serum gastrin measurements and the secretin provocation test. Other endocrine adenopathies should be excluded. An attempt is then made to localize the tumor(s) and any metastases. With techniques such as selective portal venous sampling, it may be possible to define the small group of patients with lesions amenable to surgical cure. For the remainder, continued control of gastric secretion can be achieved by H2‐receptor antagonists, but elective total gastrectomy or the combination of vagotomy with pharmacological blockade offer valid alternatives in long‐term management. Effective medical or surgical control of the peptic ulcer diathesis means that tumor progression is now the major cause of death in ZES patients, and advances in the fields of chemotherapy and radiotherapy are urgently required to control this aspect of the disease.