A distinct neurologic syndrome characterized by varying degrees of myoclonus, dysarthria, seizures, dementia, coma, and abnormal EEG occurred in 6 children with chronic renal failure. EEG findings were similar to those described in adults with dialysis dementia and consisted of diffuse slowing with bursts of 2-4 hz polyspike wave discharges. The children (4 male and 2 female) had congenital renal disorders. The encephalopathy could not be attributed to hypertension or known metabolic disturbances due to uremia. Encephalopathy occurred between the ages ot 26 months and 10 years, when renal failure was advanced (GFR 5-10 ml/min/ 1.73 m2). All had received high doses (340-800 mg/kg/day) of aluminum containing phosphate binding gels for periods of 9 months to 5 years prior to the onset of their encephalopathy. Dialysis and successful renal transplantation did not significantly alter the clinical course. The encephalopathy may be related to aluminum intoxication. However, these children differ from previously described adults with dialysis related encephalopathy attributed to aluminum toxicity in that they had not been dialyzed prior to the onset of neurologic signs. Perhaps the nervous system of growing children is more susceptible to trace metal intoxication. These observations suggest that the use of large quantities of aluminum containing gels needs reevaluation in children with renal failure. Supported by NIH grants KR-75 and RR 5624.