Uremic patients on prolonged maintenance hemodialysis (HD) therapy are at high risk for atherosclerotic cardiovascular complications. Dyslipoproteinemia which was composed of an accumulation of low density lipoprotein (LDL) subfractions, most probably due to deficiency of very low density lipoprotein (VLDL) catabolism, and an extreme decrease of high density lipoprotein (HDL) has been detected in most uremic patients mainteined HD. Three uremic patients with dyslipoproteinemia were transferred from maintenance HD to hemofiltrantion (HF). The influences of HF on their serum lipoprotein (Lp) profiles were investigated using polyacrylamide-gel (PAG) disc Lp electrophoresis, ultracentrifugal analysis and chemical methods. Improvement of dyslipoproteinemia which consisted of a disappearance or reduction of the accumulated LDL subfranctions (Sf 10-19 LDL) and a gradual increase of HDL was observed in two of the three patients within three or four weeks after introduction of HF. The results of the present study indicate that Lp profiles in some HD patients may be improved by HF therapy.