Pre dialysis concentrations of malonyldialdehyde (MDA) in the red blood cell membranes and pre and post dialysis percent variation of plasma haemoglobin levels are studied in a group of uraemic patients on maintenance haemodialysis both before and after a therapeutic trial with vitamin E. The findings show a significant correlation between MDA levels and percent variation of plasma haemoglobin during dialysis, thus indicating that reducing the amount of lipid peroxidation can help to reduce intradialytic chronic haemolysis.