The histologic features of renal osteodystrophy vary from dialysis osteomalacia to osteitis fibrosa cystica. Commensurate with this, the number of osteoblasts and osteoclasts changes with the stage of the disease; the osteoblasts are virtually absent in dialysis osteomalacia and are numerous in osteitis fibrosa. Radiophosphate accretion in bone increases with increasing osteoblastic activity, and the bone mineral status is determined by the net difference in osteoblastic and osteoclastic activity. The application of radionuclide imaging and dual radiographic absorptiometry mineral measurements in patients with renal osteodystrophy, renal transplants, and following parathyroidectomy for secondary hyperparathyroidism is reviewed.