The usefulness of intraoperative PTH monitoring in guiding adequacy of resection has been extensively documented in pHPT, whereas few data in reoperations, as well as in secondary and tertiary hyperparathyroidism, have been published. With the aim to optimize the efficacy of quick parathyroid hormone determination in the operating theatre, as well as to verify the most practical approach to PTH monitoring during parathyroid surgery, we reported our initial experience with QuiCk-Intraoperative Intact PTH immunochemiluminometric assay (Nichols Institute Diagnostics, San Juan Capistrano, CA, USA) on a portable cart directly in the operating room during 27 parathyroidectomies performed between September and December 1999 [15]. Studied population included 10 patients with pHPT (mean age 59.4 years, range 30–80), 12 end-stage renal disease patients with secondary hyperparathyroidism (46.3 years, range 30–74; average length of dialysis 118.5 months, 10–372), and five kidney transplanted subjects with tertiary hyperparathyroidism (49.8 years, range 36–64; average interval from graft 49.0 months, 25–96). There were nine reoperations (three pHPT patients, two of whom had multiglandular disease, and six recurrences in secondary and tertiary hyperparathyroidism, two due to supernumerary glands). Peripheral blood samples were taken at the induction of anesthesia, 5 to 10 minutes after resection and thereafter at times whenever judged by the surgeon. PTH results were available in a total elapsed time of 12 minutes. The mean PTH levels before and after PTx were 251.9 pg/mL (range 69–842) and 50.7 (5–184), respectively, in pHPT, 837.4 (416–1702) and 200.3 (53–440) in secondary hyperparathyroidism, and 205.6 (116–301) and 60.8 (23–97) in tertiary hyperplasias. All patients had significant percentage decline from pre-excision values regardless of the etiology of the hyperparathyroid state (mean 77.9%, 79.0%, and 68.0% in primary, secondary and tertiary cases, respectively) except one patient with recurrent secondary hyperparathyroidism (35.9% decline) whose PTH decreased from a post-excision value of 346 to 82 the day after surgery. While a reduction >50% was detected in 23 out of 27 patients after the first intraoperative sampling, additional dosages were requested by the surgeon in eight cases, including the four remaining (the one aforementioned, one secondary and two tertiary hyperparathyroidism), and two primary, one secondary and one tertiary hyperparathyroidism. According to an exponential model, kinetic analysis of PTH decay curves allowed the new post-excision PTH value to be calculated, thus rendering the interpretation of data independent of the sample timing and suggesting intraoperative PTH as the principal confirmation of adequate removal of all hyperfunctioning parathyroid tissue, at least in the earlier postoperative follow-up. On-site PTH monitoring with this user-friendly and reliable system, with a long shelf life and excellent machine stability and portability, has proved to be quite helpful in targeting PTH tests to give surgeons a timely and accurate assessment of intervention. PTH results influenced the operative approach in 29.6% (8 out of 27) of patients in our experience. Close communication and dynamic interchange with surgeons appear particularly important when multiple samples are needed. The development of optimal PTH sequence strategies with decision-focused analytical and clinical limits may improve the efficacy of “point-of-care” PTH assay and resource utilization [16].