Nine cases of primary hyperparathyroidism (PHP) in patients with urinary calculi are reported and discussed. Selective venous catheterization and parathormone (PTH) radioimmunoassay confirmed the diagnosis in all cases, preoperatively discriminated between adenoma and diffuse parathyroid hyperplasia, and permitted exact preoperative localization of 5 of 7 adenomas. The interest of the urologist in PHP and the usefulness of selective PTH radioimmunoassay are discussed and emphasized.