To evaluate the relationship between hyperparathyroid bone X-ray lesion, biochemical parameters and bone histology in chronic renal failure, 59 patients (52 +/- 14.9 years; Crs 4.7 +/- 2.2 mg/dl, mean +/- SD) on conservative treatment and 103 (48 +/- 14 years) on hemodialysis (from 48.4 +/- 36.7 months) were studied. Right-hand X-ray was carried out for evaluation of the scores (0-3) of acroosteolysis (score A) and subperiosteal resorption (score B). Serum iPTH, osteocalcin and alkaline phosphatase (AP) were measured. In addition in a subset of 53 patients, 30 in predialysis and 23 in dialysis, a bone biopsy was performed for histomorphometry. In predialysis the scores A and B correlated with bone GLA protein (BGP) (p less than 0.01), AP (p less than 0.05) and osteoid surface (p less than 0.05) and 0.01 respectively). In hemodialysis the same level of significant correlation (p less than 0.001) was found between the scores and the three humoral parameters. Score A correlated with active osteoblastic surface and active resorption surface while score B correlated with active osteoblastic surface (p less than 0.01), osteoid surface and active resorption surface (p less than 0.05). Multiple regression analysis carried out to establish the predictive variables of bone histologic lesions (active resorption surface and active osteoblastic surface) singled out BGP in predialysis and AP and the two scores in dialysis. We conclude that serum BGP, as compared to PTH and AP, prevails as a valid marker of hyperparathyroid bone lesion in predialysis, while in dialysis it does not seem to add further information to that carried by other variables.(ABSTRACT TRUNCATED AT 250 WORDS)