In order to know the pattern of renal osteodystrophy in haemodialysis patients in Saudi Arabia we conducted a multicentre study involving 209 patients. The mean age of the patients was 39.4 +/- 14 (18-70) years, 128 were males and 81 females. All patients were on acetate dialysate and their mean duration on dialysis was 3.5 +/- 1.5 years. The major symptom was bone and joint pain (25.8%). The mean serum calcium was 2.1 +/- 0.26 mmol/l, phosphorus 2.0 +/- 0.36 mmol/l, alkaline phosphatase 19.7 +/- 14.6 u/l and parathyroid hormone level was 8.9 +/- 3.9 mg/ml. The mean serum aluminium (AL) level was 25.4 +/- 17.7 micrograms/l, while that of 1,25 vitamin D3 was 8.1 +/- 4.2 ng/l and of fluoride was 92.2 +/- 31.4 micrograms/l. The major radiological finding was osteosclerosis (70%). Dual-photon absorptiometry (DPA) showed low bone mineral density (LBM) in 65% of the patients. Forty-one patients had bone biopsies with AL staining of the biopsies. Of this group, 92% had changes of hyperparathyroidism and 66% of them were pure hyperparathyroidism. Sixty percent of them had variable degrees of AL intoxication. The radiological skeletal survey of those patients could detect abnormalities in only 46% while 70% of them had abnormal bone mineral density (BMD). In conclusion, osteosclerosis is the commonest radiological finding in our dialysis patients while secondary hyperparathyroidism is the main histopathological diagnosis in bone biopsy, even in patients with normal skeletal survey. AL intoxication is a significant problem in our population. DPA is more sensitive in detecting bone abnormalities than X-radiography.