Plasma triglycerides and cholesterol were measured in controls, non-dialyzed patients with chronic renal insufficiency and uremic patients receiving either regular hemodialysis or hemofiltration treatment. Normal and elevated cholesterol levels remained generally unaffected by chronic hemodialysis and hemofiltration as well. Whereas long-term hemodialysis even up to 59 months (home-dialysis) was unable to improve hypertriglyceridemia, patients undergoing regular hemofiltration showed a prolonged decrease in plasma triglycerides. In one case, excessive hypertriglyceridemia still existing after five years of chronic hemodialysis could be normalized by hemofiltration.