This study was conducted to determine the efficacy of vigabatrin in children with epilepsy. Sixty-one children with various types of severe epilepsy were studied. In 12 children vigabatrin was introduced as monotherapy, while in 49 it was added to other antiepileptic drugs. Following the introduction of vigabatrin, 17 patients became seizure free, and 19 responded with a greater than 50% reduction in seizure frequency. The following types of epilepsy responded favorably to treatment (in order of decreasing efficacy): West syndrome, especially if secondary to Tuberous Sclerosis; cryptogenic and symptomatic partial epilepsy; Lennox-Gastaut syndrome, and other symptomatic generalized epilepsy. Optimal responses were found with vigabatrin doses of 30 to 50 mg/kg/day. Forty-one responders continued on vigabatrin, with generally good efficacy. Vigabatrin tolerability was good; in only 6 children was treatment discontinued because of side-effects such as somnolence, irritability, weight gain, and cutaneous rash. This study shows that vigabatrin is effective in the treatment of refractory epilepsy, especially in West syndrome secondary to Tuberous Sclerosis, partial epilepsy, and Lennox-Gastaut syndrome. Further studies are needed to analyze the increased frequency of seizures and the appearance of new seizure types associated with vigabatrin treatment.