Vagus nerve stimulation is the first electrical stimulation therapy for epilepsy. While its clinical use was approved by the European Union in 1994 and by the United States in 1997, it was approved last year and coverage by public insurance started last July in Japan. Owing to less invasiveness and broad indication, it is expected that vagus nerve stimulation will be increasingly used in Japan as well. Its efficacy for refractory partial seizures in patients older than 13 years was validated by two randomized control trials. Although it has been used for children and generalized seizures broadly, the efficacy for these subpopulations of patients has not been validated by randomized control trials, necessitating those studies in the near future. Afferent neural impulses generated by vagus nerve stimulation transmit to the solitary tract nucleus, then via multiple pathways including the monoamine system, vagus nerve stimulation affects the excitability of the cortical neurons. It likely exerts the anti-epileptic and anti-seizure effects using these pathways, but the detailed mechanisms underlying the effect remains to be elucidated further in future.