An audit of parathyroidectomies carried out at the East and North Herts Trust between 2010 and 2014 revealed a 25% failure rate following surgery. The audit revealed inappropriate pre-operative workup with regards to biochemistry and/or imaging in 40% of cases. In 2015, a parathyroid MDT was established. The aim of this was to ensure patients had appropriate investigation prior to referral for surgery. A Trust hyperparathyroidism pathway was written based on best practice and available evidence. The guideline advocated full initial biochemical workup and exclusion of alternate diagnoses. Imaging (USS and standard Sestamibi) was to be carried out if the biochemistry was in keeping with primary hyperparathyroidism and if the patient was a candidate for surgery. If there was discordance in imaging, a SPECT CT was performed. All patients were discussed at the MDT. An audit of the first three years revealed a significant improvement in outcome (0.050.15% failure rate following surgery). The audit also demonstrated a benefit of third line imaging, in particular, SPECT CT. In cases where there was discordance between USS and Sestamibi (33% of cases), where a SPECT CT was carried out, this led to gland localisation in the majority of cases and this in turn led to localized surgery and a successful outcome. Of interest, despite the reported rarity of familial hypocalciuric hypercalcaemia (FHH), a significant prevalence of this disorder was recognised with 5 new cases of FHH1 and the rarer FHH3 diagnosed. New NICE guidelines for hyperparathyroidism assessment and management suggest MDT discussion only if patients have unsuccessful surgery. However, this audit demonstrates the benefits of pre-surgery MDT and the significant improvement in outcome.