CASR and neonatal severe primary hyperparathyroidism: Neonatal severe hyperparathyroidism (NSHPT) is an extremely rare disorder with prevalence of 2-5 cases per 100,000.1, 2 It is caused by inactivating mutations of calcium-sensing receptors (CaSR) present on parathyroid gland which modulates the inhibitory feedback of parathormone (PTH) release thus resulting in uncontrolled hyperparathyroidism with severe hypercalcemia.3, 4 Parathyroidectomy is a definitive treatment.5 We report anaesthetic management of two children with NSHPT, scheduled for total parathyroidectomy.