Background: The importance of vitamin D was recently emphasized when it was reported to be involved in cell differentiation, proliferation, immune function and important for optimal function of many organs and tissues throughout the body, including the central nervous system. This vitamin may reduce seizure frequency and treating adverse effect of anticonvulsant drugs so its supplementation is associated with decreased seizures as it regulates pro-convulsant and anticonvulsant factors. Aim: A case-control study had been carried out to determine serum vitamin D level and other biochemical parameters in epileptic children and study it's relation to some selected variables who were treated with antiepileptic drugs for at least 6 months. Methods: Thirty seven epileptic patients who had normal age - appropriate development; visited the out patients neurological clinic in Basra General Hospital, their ages ranged from 2-14 years from the1stof February to the end of July 2014. Forty four apparently healthy children and adolescent; were age and sex matched as a control group. Information regarding history of epilepsy; age of diagnosis, type and frequency of seizures over the past 3 months and type of antiepileptic drugs were recorded. All patients were under went physical examination including general and systemic examination. Growth parameters were assessed and body mass index (BMI) was calculated and applied to appropriate growth charts. A list of investigation was measured as; serum calcium, phosphorus, alkaline phosphatase and serum 25-Hydroxy vitamin D. Results: Mean age of epileptic patients and control group was (7.67 ± 3.23) and (7.68 ± 3.5) year respectively. Two third of patients were younger than 10 years, as well as (86.5%) have normal body mass index, approximately 50% of patients received carbamazepine treatment for epilepsy and the duration of anti-epileptic drugs' therapy more than 24 months and more than 80% of patients were on monotherapy and were well controlled. The mean serum level of vitamin D was significantly low in epileptic patients than control group (21.41 ± 2.90), (67.59 ± 2.13) respectively as well as in children treated with polytherapy than those with monotherapy for epilepsy with higher level of alkaline phosphatase in epileptic patients than control group (299.09 ± 67.67) (122.21 ± 29.59) respectively (P value 0.000). On the other hand; levels of Calcium and phosphorus, serum level of blood urea and alanine aminotransferase (ALT) were not significantly differ among epileptic patient and control group (p value >0.05). Conclusion: Children and adolescents treated with anti-epileptic drugs especially those patients on polytherapy therapy should given supplements of vitamin D to satisfy their bodies requirement.