The spectrum of parathyroid disease; primary hyperparathyroidism; making the diagnosis of primary hyperparathyroidism; pre-operative parathyroid localization; preparation for surgery; involving the pathologist; choice of instruments and sutures; assistance; anatomy and embryology; findings at parathyroid exploration; the anaesthetic; preparation and towelling; siting the incision; mobilizing skin flaps; approaching the thyroid; looking for parathyroids; total thyroid lobectomy; when to discontinue the exploration; four-gland hyperplasia; secondary and tertiary hyperparathyroidism; parathyroid carcinoma; closure after parathyroid exploration; postoperative care; care of the wound; hyperparathyroid crisis; re-operative parathyroid surgery and localization techniques; technique of thymectomy; multiple endocrine neoplasia. Appendices 1 - instruments; 2 - sutures.