Parathyroid crisis, also known as a parathyroid storm, is a rare and serious complication of primary hyperparathyroidism. Four cases are reported here in which patients presented to hospital with general complaints due to hypercalcemia secondary to hyperparathyroidism. Blood test results upon admission showed high levels of serum calcium and parathyroid hormone, and medical treatment initiated to lower the calcium level was ineffective. After relevant investigations, each patient underwent surgical exploration of the parathyroid glands, followed by excision of a pathological parathyroid tumor. There was a prompt decrease in parathyroid hormone level immediately after surgery. Histology reports revealed that patients had parathyroid adenoma. All patients recovered after surgery, with serum calcium levels restored back to normal and with resolution of all symptoms of hypercalcemia. This report illustrates how often this disease is initially misdiagnosed, and how prompt appropriate surgical treatment provides the best outcome for the patient.