목적: To evaluate the accuracy of ultrasound(US), computed tomography(CT) and 99Tc sestamibi scan(MIBI) for preoperative localization of solitary parathyroid mass in patients with primary hyperparathyroidism and identify the case of Hungry bone syndrome. 방법:In a retrospective study of 58 consecutive patients with primary hyperparathyroidism, all patients underwent parathyroidectomy. Patients were performed ultrasound, computed tomography and Technetium-99m sestamibi scan before surgery. The accuracy of preoperative imaging was compared to intraoperative surgical findings. We also recorded serum calcium, serum parathyroid hormone(iPTH) and associated symptoms for Hungry bone syndrome. 결과:All 58 patients were enrolled and they had single solitary parathyroid mass. In final pathologic results, 40 patients had solitary parathyroid adenoma, 13 patients had nodular hyperplasia and 5 patients were diagnosed as parathyroid cancer. Accuracy of US was 93.8%(45/48), CT was 89.3%(50/56), MIBI was 80.4%(37/46). The combination of US, CT, MIBI had accuracy of 96.6%. Postoperative numbness was observed in 4 patients and they were treated with calcium supplementation but not persisted longer than 4th day postoperatively. 결론:Our results show that the combination of US, CT, MIBI has novel benefits for preoperative localization of parathyroid mass in primary hyperparathyroidism. A prospective randomized study is needed.