Parathyroidectomy was carried out in 26 patients over a 14-yεar period. Excellent results were obtained in patients with severe hyperparathyroidism. Vascular calcification, hypercalcaemia and pruritus did not justify surgery unless associated with unequivocal hyperparathyroidism. 13 patients required intravenous calcium infusion for up to 2 weeks to control post-operative hypocalcaemia. Calcium requirements could be predicted from the pre-operative plasma alkaline phosphatase level. Following operation continued treatment with vitamin D was necessary to prevent hypocalcaemia. Hyperparathyroidism recurred in 1 patient after 8 years and 4 patients developed osteomalacia. Since parathyroid hormone may have toxic effects other than those on bone, maintenance of normal levels should be a long-term objective in the treatment of patients with chronic renal failure. Where large parathyroid glands are present, surgical reduction in gland mass is a logical prelude to long-term suppression of parathyroid hormone with vitamin D and phosphate-binding agents.