Phenytoin, a common anti-seizure drug, leads to cosmetically unacceptable side effect of gingival overgrowth in a significant number of patients. There is some evidence of therapeutic effect of folic acid in cases of established phenytoin induced gingival overgrowth. In this study, the aim is to study the prospective preventive effect of low dose oral folic acid supplementation on phenytoin induced gingival overgrowth in epileptic children.