Prevention, diagnosis and treatment of renal osteodystrophy are continually evolving. We submitted a postal questionnaire to all Spanish dialysis centres, comprising 30 questions, with the aim of obtaining information about the current management of this entity in Spain. The answers from 171 centres, 63% of the total registered (10,724 patients), were analysed. The centres performed an annual average of nine calcium and phosphorus determinations, three for parathyroid hormone (PTH), 1.5 for aluminium and one for bone radiology. For these parameters, nephrologists consider ideal levels to be 10-10.5 mg/dl for calcium (53% of centres), 4.5-5.5 mg/dl for phosphorus (77%) and 120-150 pg/ml for iPTH (75%). The calcium concentration used in the dialysis fluids was found to be variable: 2% of the centres used 2 mEq/l, 44% used 2.5 mEq/l, 28% used 3 mEq/l and 26% used 3.5 mEq/l. When using oral calcitriol, 82% of the centres do not change the calcium concentration in the dialysis fluids; this percentage falls to 51% when calcitriol administration is parenteral. In 78% of centres, vitamin D treatment was started when PTH was high, without taking into consideration the plasma calcium level. The dose varies; in 28% of the centres calcitriol pulse therapy was started when iPTH was >250 pg/ml; 52% when >500 pg/ml and 16% when >750 pg/ml. Seventy one percent of the centres claim to use calcitriol in doses proportional to the severity of hyperparathyroidism. With regard to response to treatment, 78% of the centres wait for 6 months before considering a patient as a 'non-responder' and 80% of the centres would carry out parathyroidectomy only when iPTH is >750 pg/ml. The data collected from the enquiry show that there are important variations in some aspects related to current patient management in the different units in Spain. Diagnostic criteria are relatively homogeneous whereas the therapeutic guidelines are less uniform.