Pancreatic islet cell tumours and carcinoids are rare, and patients with these tumours form a small part of the case-load of the anaesthetist who regularly undertakes anaesthesia for major abdominal surgery. Insulinoma is the commonest functioning pancreatic neuroendocrine tumour (NET). Gastrinoma is the second commonest functioning pancreatic neuroendocrine tumour, and contrasts with insulinoma in several respects. The absence of symptoms is characteristic of non-functioning tumours. VIPoma is a rare tumour. Secretion of Vasoactive Intestinal Polypeptide produces watery diarrhea. Major upper abdominal surgery involves a bilateral subcostal incision, may last for several hours, requires dissection of lymphatic tissue and causes fluid shifts. It occasionally results in severe blood loss. A. Holdcroft has described a pre-operative checklist for the additional problems of the patient with a NET. Pre-operative investigations include pulmonary function tests, ECG, full blood count, clotting screen, electrolytes and liver function tests.