A syndrome of profuse watery diarrhea, hypokalemia, and hypercalcemia, without gastric hypersecretion or ulcer is associated with pancreatic adenoma. Excision of a parathyroid adenoma and then hyperplastic parathyroid tissue temporarily relieved symptoms and restored serum calcium and serum potassium values to normal. The profuse watery diarrhea, hypercalcemia, and hypokalemia were permanently relieved by excision of a large pancreatic adenoma after recognition of the syndrome. The genetic aspects of this syndrome were demonstrated in the case presented. Of 14 members on the patient's paternal side, three had pancreatic adenomas, six had renal stones, and five had intractable peptic ulcers. Endocrine adenomas, frequently multiple, were seen in the patient and in two relatives.