From 1978 to 1990 subtotal parathyroidectomy was carried out on 41 patients for secondary hyperparathyroidism. The indications for parathyroidectomy and suitable operative time, especially in the point of view of renal osteodystrophy are discussed. Serum ALP and PTH level and the presence of generalized fibrous osteitis were good indicators for parathyroidectomy. Furthermore, 99mTc-Pyrophosphate bone scintigraphy and Dual Photon Absorptiometry were proved to be valuable for patient selection for parathyroidectomy. Parathyroidectomy for patients in whom 99mTc-pyrophosphate bone uptake is diminished or patients in whom bone mineral contents are dramatically decreased must be carefully performed.