Alteration in serum lipids leads to atherosclerosis. Antiepileptic drugs alter serum lipids. The effect of carbamazepine therapy on serum lipids of children with partial epilepsy and correlation of changes with carbamazepine level was prospectively studied. The study population of 29 children (16 male, 13 female; age range, 3-12 years) diagnosed with partial epilepsy were enrolled within 14 days of starting carbamazepine. Serum lipids were measured at enrollment and at 3 months. Carbamazepine levels were determined at 3 months of therapy. Mean total cholesterol was 130.2 +/- 27.3 mg/dL at enrollment, and increased significantly to 144.8 +/- 32.9 mg/dL at 3 months (P = 0.018). There was a significant change in mean low and very low density lipoproteins, and in triglycerides (P < 0.05). Both the ratio of total cholesterol to high density lipoprotein and the ratio of low density lipoprotein to high density lipoprotein increased significantly. There was no significant change in levels of high density lipoprotein. At 3 months, mean carbamazepine level was 6.5 +/- 1.8 microg/dL. Changes in serum lipids did not correlate with serum carbamazepine level (P > 0.05). Carbamazepine therapy increases levels of lipids that increase the risk of atherosclerosis.