Introduction: This study aims to investigate the effects of oxcarbazepine on hematological parameters, renal, liver, thyroid functions, plasma electrolyte, lipid, lipoprotein (a), vitamin B12 and folic acid levels. Methods: Fifteen idiopathic partial epilepsy patients were included in this study. Three patients were excluded from this study because of irregular drug use (n=1) and the requirement of additional antiepileptic treatment due to resistant epilepsy (n=2). Blood samples were taken in the morning following a 12-hour fasting period. Serum samples were examined as for hematological parameters, sodium (Na), potassium (K), calcium (Ca), phosphorus (P), glucose, blood urea nitrogen (BUN), alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT), total cholesterol, triglyceride, low density lipoprotein-cholesterol (LDL-K), high density lipoprotein-cholesterol (HDL-K), apolipoprotein A (Apo-A), apolipoprotein B (Apo) -B), lipoprotein a (Lp a), free and total triiodothyronine (T3), tetraiodotyrosine (T4), thyroid-stimulating hormone (TSH), folic acid and vitamin B12 levels at the beginning of treatment, at the 3 rd , 6 th . and 12 th months. Results: Significant changes were not detected in hematologic parameters, Na, K, Ca, P, glucose, BUN, AST, ALT, ALP, total cholesterol, triglyceride, LDL-C, HDL-C, Apo-A, Lp (a), fT3, TSH, folic acid and vitamin B12 levels at the 3 rd , 6 th , and 12 th months of treatment. A statistically insignificant increase in GGT and a statistically insignificant decrease in fT4 levels were detected at the 3 rd , 6 th ,12 th months. A significant increase was detected in Apo-B levels at the third month of treatment, which returned to normal limits at the 12 th months. There was a statistically significant increase in Lp (a) levels at the 12 th month compared to baseline and the 6 th -month values (p<0.05). Discussion and Conclusion: We suggest that liver enzymes, thyroid function tests and Lp (a) levels, which are risk factors for atherosclerosis, should be monitored in children using oxcarbazepine.