Various neurological complications may occur in patients under haemodialysis for end-stage chronic renal failure. Their frequency has clearly been reduced by improvements in the modalities and techniques of dialysis. Some of these complications are related to uremia and/or to the accumulation of endogenous toxic substances the nature of which has not been elucidated (e.g. uraemic encephalopathy, polyneuropathy), while others are directly due to the haemodialysis itself (e.g. dialysis disequilibrium syndrome, aluminum encephalopathy).