A 30-year-old previously healthy woman was diagnosed as having a vasoactive intestinal polypeptide (VIP)-producing tumour of the pancreas. Her medical history was typical for neuroendocrine gastrointestinal tumours, presenting initially with non-specific symptoms but eventually she developed life-threatening manifestations requiring intensive care due to severe dehydration. She immediately recovered following surgical resection. The patient had elevated serum concentrations of VIP as well as pancreastatin, and post-operatively elevated concentrations of three growth factors, IGF-I, EGF and TGF-°, were seen. The importance of the alterations in plasma concentrations of the different peptides for her symptomatology are discussed.