The patients treated with hemodialysis have marked cardiovascular morbidity and mortality. Furthermore, lipid and lipoprotein disorders in these patients are well known. Since lipid and lipoprotein disorders are undoubtedly associated with cardiovascular morbidity and mortality, treatment of this group of patients should aim also at the correction of these disorders. The effect of hemodialysis with cellulose diacetate membranes on plasma lipids and lipoproteins was studied in 13 female patients followed-up for 4.5 months. Total cholesterol, triglycerides, HDL and LDL cholesterol, and apolipoproteins (a), AI and B were determined in each patient at the beginning and at the end of the study. Significant increases in HDL cholesterol (0.95 +/- 0.30-1.09 +/- 0.32 mmol/l), apolipoprotein B (1.14 +/- 0.35-1.35 +/- 0.36 g/l), and apolipoprotein (a) (272.38 +/- 281.66-357.36 +/- 400.30 U/l), nonsignificant increases in total cholesterol (5.61 +/- 1.18-5.63 +/- 1.23 mmol/l), LDL cholesterol (3.30 +/- 1.05-3.69 +/- 1.32 mmol/l) and apolipoprotein AI (1.03 +/- 0.25-1.11 +/- 0.19 g/l), and nonsignificant decrease in triglycerides (3.07 +/- 1.49-2.74 +/- 1.37 mmol/l) were found in the study. In conclusion, only some of the observed changes in plasma proteins and lipoproteins are beneficial for the patients.