Serum lipids, lipoproteins and apolipoproteins A and B were measured in 101 epileptic patients receiving chronic treatment with valproic acid, carbamazepine or phenobarbital and in 75 age- and sex-matched control subjects. In relation to controls, subjects treated with valproic acid showed significantly lower values of total and LDL-cholesterol levels; subjects treated with carbamazepine showed significantly higher values of HDL-cholesterol and apolipoprotein A concentrations and subjects treated with phenobarbital showed significantly higher values of total cholesterol, HDL-cholesterol, apolipoprotein A and apolipoprotein B levels. The total cholesterol/HDL-cholesterol ratio was significantly lower in patients receiving valproic acid or carbamazepine but not in the phenobarbital-treated group. Changes in serum lipids profile did not correlate with drug plasma concentrations nor the duration of the treatment.