Osteomalacia without marked elevations of parathyroid hormone (PTH) has been described in maintenance dialysis patients. The proposed etiology has centered upon the transfer of an environmental agent (aluminum) from the dialysis water system. The present report describes an azotemic patient, who, prior to the initiation of dialytic therapy, presented with severe osteomalacia and low PTH concentrations for the severity of renal failure. The osteomalacia was documented by bone histology on two occasions 1 year apart, and aluminum deposits at the osteoidmineralized bone interface were demonstrated with histologic techniques. PTH concentrations were within the normal range (less than 0.1 ng/ml) on three widely spaced intervals. No definite statement can be made regarding the etiology of the osteomalacic syndrome in this patient, but maintenance dialysis does not appear to be necessary for its expression.