The aim of the study was to recapitulate the experience of the authors in the employment of two minimally invasive parathyroidectomy (MIP) techniques: video-assisted according to Miccoli (MIVAP) and open according to Udelsmann (OMIP) as the procedure of choice in primary hyperparathyroidism resulting from parathyroid adenomas.Material and methods. The investigation included 168 patients qualified for MIP between December 2002 and April 2007, diagnosed as primary hyperparathyroidism and presenting with a single parathyroid adenoma detected in at least one imaging examination (USG and/or 99m Tc-MIBI subtraction scintigraphy). In group A (n=100), the procedures were performed employing the MIVAP technique with intraoperative serum parathormon determinations (IOPTH), while in group B (n=68), the OMIP technique was used in combination with IOPTH. The analysis included surgical indications, the course of the procedure, the validity of intraoperative histopathology in identifying multiglandular disease, the validity of IOPTH in selection of an appropriate extent of neck exploration, and the surgical outcome.Results. Postoperative normocalcemia was achieved in 99% vs 100% of patients, respectively (A vs. B). In nine patients subjected to MIP, intraoperative IOPTH allowed for detection of multiglandular disease. IOPTH proved to be significantly more effective in identification of patients with multiglandular disease as compared to intraoperative examination of a single resected parathyroid gland, which had been demonstrated by imaging studies to be a single adenoma (the accuracy of 98.8% vs. 92.8%, respectively). The conversion rate was 5% and 5.8%, respectively (A vs B). A significantly higher percentage of visualized recurrent laryngeal nerves was noted in group A vs B (88% vs 66%, respectively), although the prevalence of transient recurrent laryngeal nerve palsy was similar in both groups (1% vs 2.9%). The investigators also observed a decrease in pain-associated complaints (by the mean value of 25%) and a decreased demand for analgesic drugs (by the mean value of 50%) on the first postoperative day. Satisfaction of the cosmetic effect was higher in the first postoperative month in group A vs B, although the difference became non-significant after 6 months.Conclusions. Both techniques, MIVAP, as well as OMIP, are highly effective in surgical treatment of patients with primary hyperparathyroidism caused by a single adenoma. However, the use of IOPTH is necessary when the results of preoperative localization examinations are not complementary in order to minimize the risk of inadvertently missing multiglandular disease. The advantage of MIVAP consists in easier identification of the recurrent laryngeal nerve, a decreased pain and decreased demand for analgesic drugs after the surgery, as well as a better cosmetic effect in the early postoperative period resulting from a smaller scar size.