Plasma lipids and lipoproteins obtained from different places of the circuit of double filtration plasmapheresis (DFP) were measured and effect of DFP therapy on removal of them was examined. When 2A was used as a second filter, 69.8%, 52.4%, 63.0%, 58.0%, 60.8%, 59.2% and 63.9%, respectively of β- lipoprotein, cholesterol, triglyceride, high density lipoproteins (HDL), phospholipids, free cholesterol and lipoprotein (a) (Lp(a)) were removed from the patient's plasma. When 4A was used as a second filter, 69.0%, 56.8%, 53.2%, 45.4%, 56.0%, 50.9% and 51.7%, respectively of β-lipoprotein, cholesterol, triglyceride, HDL, phospholipids, free cholesterol and Lp(a) were removed from the patient's plasma. In contrast, concentrations of free fatty acids (FFA) after DFP therapy using filter 4A and 2A increased to 222.8% and 256.4%, respectively. Thus, it was shown that except for FFA, DFP therapy using either 2A or 4A as a second filter is effective in reducing concentrations of plasma lipids and lipoproteins.