The authors present their experience of surgery for persistent hyperparathyroidism in renal transplant recipients, based on a series of 944 patients transplanted between 1983 and 1992. 56 patients underwent subtotal parathyroidectomy for persistent secondary hyperparathyroidism. Control of serum calcium was excellent in 83% of patients: 2 patients retained a well controlled hypocalcaemia, 2 are still hypercalcaemic and 3 others have developed recurrent hyperparathyroidism. The postoperative course was marked by one death not related to parathyroidectomy and one recurrent laryngeal nerve palsy. Subtotal parathyroidectomy combined with removal of the thyrothymic tissue is an effective operation to control phosphorus and calcium metabolism in patients with persistent hyperparathyroidism after renal transplantation.