Vigabatrin (VGB) is one of the most effective anti-epileptic drugs for tonic spasms, those accompanied with tuberous sclerosis complex (TSC), but is not available in Japan. We treated 7 patients with West syndrome (WS) and TSC with VGB. In these patients, VGB treatment was started at 5-65 months of age. Six patients (86%) had complete cessation of tonic spasms. Of these, 3 patients had complete cessation within 24 hours after VGB treatment. The mean initial dosage of VGB was 36.2 mg x kg(-1) x day(-1), and the mean maintenance dosage was 38.4 mg x kg(-1) x day(-1). At the beginning of VGB treatment, 3 patients had hypsarrhythmia, 2 had focal discharge with generalization, and 2 had only focal discharge on electroencephalography. Hypsarrhythmia disappeared within 4-8 weeks after VGB treatment. Behavioral problems and sleep difficulty were observed in 6 patients. Visual field examination revealed no abnormalities in 3 patients. We hope that patients with WS and TSC can be treated with VGB as soon as possible in Japan.