Purpose:This study is to evaluate the efficacy and safety of vagus nerve stimulation (VNS) in intractable childhood onset epilepsy by reviewing our experiences. Mehthod:Involved in the study are five patients who underwent VNS from July 23th, 1999 and had been followed up over 12 months. We reviewed data prospectively collected with a focus on clinical features, therapeutic outcomes and safety, developmental progress, and EEG findings. Results:Three patients were classified as Lennox-Gastaut syndrome. One patient of the two remaining patients had gelastic seizure caused by hypothalamic harmatoma, while the other patient had partial seizure with secondary generalization. Among the 5 patients, one patient showed a seizure frequency reduction rate of about 50% from baseline in 3 months after VNS implantation and more than 90% in 12 months, 2 patients of about 50% in 3 months and of about 75% in 12 months, but the other two patients didn’t show any change in seizure frequency. Side effects such as hoarseness, dyspnea during sleep and wound infection could be controlled simply through the adjustment of output current or wound revision. However, efficacy in cognitive function and EEG findings was not satisfactory. Conclusions:VNS might be an effective adjunctive therapy for intractable childhood epilepsy and transient side effects can be controlled without discontinuation of VNS therapy.