The influence of chronic antiepileptic treatment on total and conjugated bilirubin, lipid profile, and calcium and magnesium plasma levels was investigated in 294 adult epileptic outpatients undergoing different antiepileptic therapies. A comparison was made with an age- and sex-matched control group. All the antiepileptic groups, excluding the sodium valproate group, showed a significant reduction in total and conjugated bilirubin and a significant increase in total cholesterol and low-density lipoprotein (LDL) cholesterol levels in comparison to the controls. The high-density lipoprotein (HDL) level in the valproic acid group was significantly lower than that in the controls, although no difference was found between the therapeutic groups and the controls for triglycerides, calcium, and magnesium. Our findings indicate that before beginning any antiepileptic treatment, the lipid profile should always be taken into consideration and should be regularly checked throughout the treatment.