Introduction: One of the most important problems in the treatment of epileptic patients is the drug effects. Na Valproate is a widely used drug for the treatment of epilepsy. The side effects of the drug include digestive disorders, increasing liver enzymes, fatal hepatitis, cognitive disorder, behavior disorder, insomnia, hyperactivity, tremor, stupor and coma, metabolic disorders, hair waving, curling, thinning and loss, pancreatitis, blood effects, fetal hydatoine syndrome, irregular menstruation and secondary amenorrhea.Material and Methods: In this descriptive study 170 patients with epilepsy were evaluated. These patients were referred to Neurologic clime of Imam Reza Hospital over a period of 3 years from September 1996, and treated with Na Valproate. Sixty-five percent of patients were male due to the fact that females avoid Na Valproate during the fertility period, Our study was done to determine complications of Na Valproate, and the following complications developed in our patients transient neutropenia as the most common complication, 12 cases (7% ), weight increasing, 7 cases (4%), diminished appetite, 4 cases (2.5%), tremor, 1 case, abdominal pain, 1 case, and ALP increasing, 1 case.Conclusion: Regarding to the limited side effects of Na Valproate and its good therapeutic effects in controlling different types of epilepsy, it is suggested that this drug is very effective in treatment of epilepsy except of children aged less than 2 years and women who are in the fertile ages.