We present four cases with clinical and biochemical hypocalcaemia and evidence supportive of hypoparathyroidism. One case had been previously ascribed a diagnosis of idiopathic hypoparathyroidism. Following the detection of relative hypercalciuria, all cases were found to have autosomal dominant hypocalcaemia with hypercalciuria and mutations of the calcium-sensing receptor gene, of which two were novel. Increased awareness of this condition and access to genotyping enables prompt accurate diagnosis and cascade screening of first-degree relatives.