The use of a hand-held gamma probe during the operation allows a direct approach to the parathyroid adenoma, which is more active than the thyroid. This procedure is significantly less morbid and can be performed in shorter time than standard neck exploration. Hand-held gamma probe already existed at the Department of Oncology and Nuclear Medicine. As a result of a very good cooperation with Department of Internal medicine and Department of Othorhinolaryngology, for the first time in our country minimally invasive radioguided parathyroidectomy was performed on April 16th, 2002. Until now, 15 patients with primary hyperparathyroidism underwent this type of operation. 700 MBq 99m-Tc-SESTAMIBI was injected two hours before the planned operative procedure. Preoperative scintigraphy was performed 10 and 80 minutes after the administration of radiopharmaceutical. This study deals with our first experience of intra-operative localization of parathyroid adenomas using a hand-held gamma probe, as well as our observations concerning the selection of the patients.