We retrospectively assessed the long-term efficacy of vagus nerve stimulation (VNS) therapy in 31 patients with refractory partial and generalized seizures who were not candidates for resective epilepsy surgery. Following implantation of VNS there was significant improvement in seizure frequency at 6 months. Sixteen patients continued to have sustained response to VNS therapy 4 years later. Adverse effects of VNS therapy were transient and tolerable. The majority of the patients did not gain body weight and some of them had significant weight loss. Therefore VNS is safe and effective therapy and has a long-term sustained effect in refractory epilepsy.