We present a case series of three patients with primary hyperparathyroidism (PPH) who achieved sustained normocalcaemia following denosumab therapy, and subsequently outline the potential use of denosumab in the medical treatment of PPH in patients otherwise unsuitable for surgical cure. Case one, an 80 year old male presented with functional decline and was noted to have PPH and severe hypercalcaemia amongst multiple medical co-morbidities. He declined surgery given poor functional condition. A single dose of 60mg denosumab was administered following a new diagnosis of osteoporosis based on DEXA scanning. His serum calcium normalised from 3.06mmol/L to 2.32mmol/L within two weeks of treatment, and remained normal three months post dose. Case two, a 70 year old female presented with a recurrence of PPH following previous left inferior gland parathyroidectomy. She had co-existing osteoporosis and previous 10 years of bisphosphonate therapy. Her calcium levels had remained elevated despite bisphosphonate therapy and the patient was reluctant for further surgical intervention. Denosumab for her osteoporosis was initiated 60mg 6 monthly after deteriorating bone mineral density (BMD). Her calcium levels normalised within 6 months and 2 years later she remains normocalcaemic and has improved BMD. Case three, an 80 year old female with osteoporosis presents with an unstable C2 fracture following a fall. During her inpatient stay was noted to have PPH and hypercalcaemia and other clinical symptoms resulting from hypercalcaemia. Given the unstable C2 fracture surgical intervention for her PPH could not be undertaken due to unacceptable anaesthetic risks associated with neck manipulation. She received denosumab 60mg for treatment of her osteoporosis and her calcium levels normalised from 2.85mmol/L to 2.52mmol/L within one week. These cases highlight a potential role for denosumab in controlling hypercalcaemia in patients with PPH who are otherwise unsuitable for surgery.