Primary hyperparathyroidism (PHPT) is the leading cause of incidentally detected hypercalcaemia in asymptomatic individuals. Rarely, PHPT may present with severe hypercalcaemia or even hypercalcaemic crisis. We describe a case of a 53-year-old male who presented with acute severe hypercalcaemia as the index manifestation. Complete clinical, biochemical and radiological evaluation led to an eventual diagnosis of PHPT. He had a challenging clinical course as hypercalcaemia did not improve significantly despite undergoing multiple sessions of haemodialysis and other supportive measures. Furthermore, the presence of acute kidney injury precluded the use of bisphosphonates. In the end, he received subcutaneous denosumab injection and his serum calcium levels improved dramatically afterwards. Subsequently, he underwent successful parathyroidectomy. Denosumab therapy can play a critical role in managing such patients especially when other therapeutic modalities cannot adequately control hypercalcaemia.