A retrospective study of 100 patients followed for 1-4 years after successful renal transplantation was undertaken to assess the amelioration of previously present metabolic bone disease and to determine the risk factors associated with the development of osteonecrosis. 42% of patients showed some evidence of bony abnormality. Following transplantation, there was slow but progressive resolution in the X-ray changes of hyperparathyroidism but not of osteoporosis. 14% of patients developed osteonecrosis in the posttransplant period with the femoral head the most common site involved (72% of patients). Osteonecrosis could not be related to average steroid dose, number of steroid pulses, or the preexistence of metabolic bone disease.