Total and regional bone mineral densities (BMD) of ten male haemodialysis (HD) patients and ten male patients on continuous ambulatory peritoneal dialysis (CAPD) were measured using dual-energy X-ray absorptiometry (DEXA), and compared with that of age- and sex-matched controls. Our data showed that patients with renal failure on dialysis had reduced bone densities as manifested by a reduction in total body BMD, femoral neck BMD, and Ward's triangle BMD. In addition, head BMD and femoral trochanter BMD were also reduced in HD patients. Among HD patients, the length of the period of dialysis correlated with serum level of parathyroid hormone and the reductions in total body BMD and head BMD. Furthermore, there was a strong negative correlation between bone density of the skull and serum parathyroid hormone. Our results demonstrated regional variations in the reduction of bone density in patients with asymptomatic renal bone disease. DEXA bone scan is a useful adjunct in the early assessment of renal osteodystrophy and bone density of the skull can be used as a monitor in hyperparathyroid bone disease.