Between 1969 and April 1975 24 patients with severe secondary hyperparathyroidism (sHPT) clinically presenting with uremic osteopathy required either total (n=5) or subtotal (n=18) parathyroidectomies, 17 patients were already supported by maintenance hemodialysis, 6 patients suffered from terminal renal insufficiency. The leading clinical symptoms consisted of general osteoporosis, spontaneous fractures, extraosseous calcifications and histologically proven dissecting fibroosteoclasia. After operation 18 patients experienced complete relief from their complaints and repair of their skeletal lesions, 2 patients required reexploration for an undetected hyperfunctioning 4th parathyroid gland, regretfully with no success. In 4 patients with subtotal parathyoidectomy a recurrence of varying intensity with increased PTH-secretion from the remnant had to be registered after months and years.-The indication for surgical treatment of sHPT due to chronic renal failure has to be based on two sets of findings: 1) inadequate longterm suppression of increased PTH secretion by conservative measures like high dialysate calcium concentration or oral calcium intake, serum phosphorus depletion by oral intake of aluminium hydroxyde and possibly also by Vit. D; 2) persistent hypercalcemia, progressive osteodystrophy and severe complaints like bone pain and pruritus.