All children had normal thyroid function before the initiation of CBZ treatment. During CBZ therapy thyroid dysfunction, with increased thyrotropin (TSH) and decreased thyroxine (T4), free thyroxine (FT4) and triiodothyronine (T3) was found, while, significant association was revealed between serum low-density lipoprotein cholesterol (LDL-C) and TSH levels at 6 (r=0.469; p=0.043) and 12 (r=0.730; p=0.001) months of treatment.