To evaluate the efficacy of topiramate (TPM) for the treatment of children with epilepsies, we introduced TPM to 45 patients whose epilepsy began in childhood and whose ages ranged from 4 months to 30 years old (mean age: 11 years 7 months). Thirteen of these patients had been diagnosed with generalized epilepsy (GE) (1 cryptogenic, 12 symptomatic), 30 with localization-related epilepsy (LRE) (7 idiopathic, 23 symptomatic), and 2 with unclassified epilepsy [1 case of severe myoclonic epilepsy in infancy (SMEI), 1 case of epilepsy with continuous spikes and waves during slow sleep (CSWS)]. The initial dose of TPM was 1.97 +/- 0.45 mg/kg/day, followed by a slow titration to the maximum dose of 7.32 +/- 1.32 mg/kg/day. After a mean treatment period of 13.5 months (range 4-20 months), the rate of reduction in seizure frequency by more than 50% [50% responder rate (50% RR)] and the rate of complete remission (seizure-free) were 53.8% and 23.1%, respectively, in patients with GE, and 73.3% and 23.3%, respectively, in patients with LRE. TPM was significantly effective against many seizure types including tonic, clonic, complex partial, myoclonic, and atypical absence seizures. Adverse effects included sleepiness in 13 cases (28.9%), weight loss in 6 cases (13.3%), and metabolic acidosis in 2 cases (4.4%); all of these effects were both mild and transient. In conclusion, TPM is effective and safe for the treatment of pediatric epilepsies.