A 74-year-old woman had secretory diarrhea, severe metabolic acidosis, hypokalemia, hypovolemia, and acute renal failure caused by a pancreatic vasoactive intestinal polypeptide (VIP)-secreting tumor. Vipoma is a rare neuroendocrine tumor. Morbidity and mortality are related to long-standing dehydration and electrolyte and acid-base disturbance resulting in acute renal failure. Diagnosis requires the documentation of large volumes of secretory diarrhea, elevated VIP plasma levels, and the localization of the VIP-secreting tumor. Metastases are present in 50% of patients at the time of diagnosis. Treatment includes correction of volume, electrolyte, and metabolic abnormalities; CVVH during ARF; pharmacotherapy to decrease gastrointestinal secretion; and surgical resection of the vipoma.