The parathyroid adenoma is the most common cause of the primary hyperparathyroidism. The characteristic of primary hyperparathyroidism is hypercalcemia and high value of serum parathyroid hormone. The primary hyperparathyroidism with parathyroid adenoma is treated by excision of parathyroid gland involved. Especially, parathyroid storm in patients with primary hyperparathyroidism is more prevalent than commonly appreciated. The symptoms and signs of the syndrome are not only due to the hypercalcemia, but also to the toxic effects of the parathyroid hormone. Its wide, but nonspecific clinical presentations make it easily confused with other cardiovascular or renal diseases. The mortality rate in untreated cases of parathyroid storm is essentially 40%. A 33 year old woman with primary hyperparathyroidism was found to have a left lower parathyroid adenoma, presented with hypercalcemic crisis. Initially, good responsiveness to a saline infusion, furosemide administration was noted. Unfortunately, she became consciousness disturbance after fine-needle aspiration of the parathyroid tumor. The recurrent storm was refractory to medical therapy, but was treated succesfully by emergent surgical removal tumor revealed a parathyroid adenoma with parathyroid hormone. Hypercalcemia was alleviated postoperatively. These observations corroborated a functioning parathyroid adenoma.