The authors present a case of a 40-year-old female patient examined repeatedly in the course of 11 years and hospitalized on account of pain in the hypogastrium, subfebrile temperatures, watery diarrhoea, hypokaliaemic alkalosis, weakness, fatigue and loss of body weight. As to laboratory examinations hypokaliaemia, hyponatraemia, metabolic alkalosis, irregularly elevated CRP values and minor leucocytosis predominated. A weight loss of cca 8 kg along with a severe mineral deficiency and clinical symptomatology called for parenteral nutrition with a mean daily substitution of 240 mmol K and 200 mmol Na. Due to the clinical condition and non-specific results of graphic and histological examinations the possibility of a VIPoma was considered. This diagnosis was confirmed by laboratory examinations and clinically--after the onset of corticoid treatment marked improvement of the general condition occurred. Finally the authors discuss diagnostic and in particular therapeutic possibilities in this disease.