The incidence of VIPoma is approximately one per 10 million population. Thus in the Czech Republic this rare disease should be diagnosed once per year. The authors present their experien- ce with the diagnosis and treatment of patient born in 1956, who suffered since 1990 from diarrho- ea, at first episodically. In 1992-1994 the diarrhoea was profuse, caused dehydration, hypokalaemia and severe metabolic acidosis without an increase of the anion gap. As a result of dehydration the patient developed acute renal insufficiency. Due to hypokalaemia he developed paroxysmal atrial fibrillation. The diagnosis was based on the clinical finding and later confirmed on laboratory examination by a high VIP serum concentration. For treatment of diarrhoea Sandostatin was used. The tumour was located only after a scan with 123I-VIP in the cauda of the pancreas. Scintigrap- hy with labelled octreotide, similarly as other imaging methods (sono, X-ray and CT) were not effective. In 1994 left-sided hemipancreatectomy was performed. Although the patient was operated four years after the onset of the disease, no secondaries were detected.After surgery the diarrhoea stopped and no further treatment was necessary.

        Key words: VIPoma - Dehydration - Acidosis - Hypokalaemia - Diarrhoea.