The relationship between acute pancreatitis and hyperparathyroidism has been described extensively in the past. Despite the rarity, the clinical progression of pancreatitis associated with hyperparathyroidism has been known to be so rapid and severe that it may cause death. When, furthermore, the pancreatitis is caused by hyperparathyroidism, the recovery from disease can be hardly expected unless the hyperparathyroidism is corrected. We present a case of acute pancreatitis in a 68-year-old man that have been caused by primary hyperparathyroidism. The clues of hyperparathyrodism were hypercalcemia and elevated parathyroid hormone, but he showed subtle or negative symptoms of hypercalcemia. After the excision of parathyroid adenoma, serum calcium level returned to normal and the symptoms and function of pancreas were recovered.