Primary hyperparathyroidism (PHP) is a benign condition characterised by malignant potential. Even in specialist wards, 5-10% of operations for PHP are unsuccessful. The main reasons seem to be ectopy of the parathyroid gland, numerous adenomas, multiglandular parathyroid hyperplasia, and intrathyroid location of the parathyroid. The last three decades have witnessed a rapid progression in imaging diagnostics.