The toxic effects of AEDs in chronic epileptic children are either CNS mediated or affect other systems in the body. It may be related to serum level of drugs or idiosyncratic effect. The aim of this work is to asses the frequency and extent of neurotoxic and systemic toxic effects of AEDs in relations to seizures, serum drug level and EEG findings in 56 chronic epileptic children received AEDs for more than one year. All patients were subjected to history examination, laboratory tests, quantification of AEDs in serum, EEG and Toxicity rating scales. Results: There were significant increase in toxic effects of AEDs in children received polytherapy and also in those with toxic serum level of AEDs. The incidence of cerebral dysrhythmia in EEG more with toxic serum level. The highest toxicity was with patients received combined doses of Na valproate & clonazepam and least with CBZ or LTG. Conclusion: Monotherapy had fewer side effects than polytherapy. Toxic serum level had toxic effect on CNS mainly and other systems. CBZ and LTG were the safest drugs.