Success following initial parathyroid surgery is high at approximately 95%. Developments in preoperative imaging techniques and subtle variations in parathyroid surgical approach have marginally improved already high success rates. However, failed initial neck exploration or true later recurrence of primary hyperparathyroidism (PHPT) can be difficult to manage. The initial consideration is always to ensure that the diagnosis of PHPT is secure and it is prudent to re-evaluate the biochemical diagnosis before further imaging or attempts at surgery. The recent NICE guideline on primary hyperparathyroidism, NG132, recommends that failed initial parathyroid surgery or recurrences should be managed within an MDT setting of experienced clinicians in parathyroid disorders at centres with such experience and expertise. Imaging modalities may be different in the setting of failed initial neck exploration and certainly the surgical skills required for successfully re-exploring a previously explored neck are different to de novo cases. Failure to localise parathyroid adenomas poses significant problems in management and occasionally primary medical therapy such as cinacalcet may be required, at least as a holding measure while further imaging modalities are explored. The threshold for surgical intervention may be different following failed initial neck exploration or later recurrence of PHPT, dependent upon specific circumstances and underlying diagnoses, such as syndromic associations. The talk will cover the difficulties and challenges in managing patients with failed initial neck exploration and later recurrence of PHPT and where feasible, will be based around NICE Guideline 132.