Thirty children (20 males, 10 females) with intractable epilepsy received vigabatrin (VGB) as an open label basis to preexisting antiepileptic drugs. The seizure types consisted of generalized tonic clonic seizure [10], complex partial seizure [8], myoclonic seizure [7], and mixed type with simple partial seizure, complex partial seizure and/or generalized seizure [5]. The cause of the epilepsy was cryptogenic in 16 and symptomatic in 12. The current dosage regime of anticonvulsants were maintained during the trial period. VGB at 40-80 mg/kg/day were titrated according to the clinical response for a period of 2-24 months. The result of treatment was categorized as 'responders' with 13 (43%) having 50-75% reduction of seizure frequency; and 'non-responders' which consisted of 17 children. There was no relationship between outcome of VBG add-on therapy and the sex, age of onset, type of seizure, type of epileptic syndrome, etiology, associated neurological abnormality, mental retardation or abnormal brain CT/MRI findings.