Although primary hyperparathyroidism is a rare disease in Korea, the incidence is increasing gradually due to increased concern and the development of laboratory and imaging techniques. Previous radiological imaging studies for localization of a parathyroid adenoma have been generally unreliable. Recently, preoperative administration of Tc-99m sestamibi has improved detection of parathyroid adenomas. Combining preoperative administration of the sestamibi radionuclide with an intraoperative gamma probe can identify the exact location of a parathyroid adenoma successfully and facilitate a safe and efficient operation under local anesthesia. Limited exploration provides a better cosmetic result while decreasing the potential complications of bilateral exploration. Also, an obvious indication for radio-guided para thyroid surgery with a minimal approach may well be the high-risk patient who cannot tolerate a general anesthestic or an extensive surgical approach. We report three cases of primary hyperparathyroidism which were successfully treated with intraoperative radio-guided parathyroid surgery. These parathyroid surgery can be enhanced especially in the future, when and if an efficient and cost-effective intraoperative PTH assay becomes available.