Primary hyperparathyroidism (PHPT) is due to a single adenoma in 85%-95% of cases, and is often cured after adenoma removal. Intraoperative rapid determination of intact parathyroid hormone (PTHio) may be a tool for monitoring the effectiveness of PHPT surgery. The main objective of our study was to evaluate PTHio determination and to establish whether its successful implementation contributed to achieve minimally invasive surgery (MIS) and major ambulatory surgery (MAS) in the treatment of PHPT. Retrospective study of a consecutive series of patients diagnosed and operated on for PHPT at the University General Hospital of Ciudad Real between January 2005 and January 2012. In the study period, 91 patients underwent surgery. 39 (42.9%) under general anesthesia, while 52 (57.1%) were candidates for regional anesthesia by cervical block. Seventy-six of all patients (83.5%) were amenable to MIS using a unilateral approach. Classical cervicotomy was performed in all other patients. PTHio determination was done in 75 patients, showing cure in the same surgery in 68 of them. MAS was performed in 70.3% (64) of patients. Determination of PTHio may allow for changing the surgical approach to PHPT at our department, allowing for performance of MIS on an outpatient basis in a significant proportion of patients with some cosmetic improvement, probably less pain, shorter hospital stay, and less potential complications than bilateral cervical exploration. Copyright © 2013 SEEN. Published by Elsevier Espana. All rights reserved.