Deep brain stimulation of the anterior nucleus of the thalamus is an effective treatment for patients with refractory epilepsy who do not respond sufficiently to medical therapy. Optimal therapeutic effects of deep brain stimulation probably depend on accurate positioning of the stimulating electrodes. Microelectrode recordings show bursty firing neurons in the anterior nucleus of the thalamus region, which confirms the anatomical target determined by the surgeon. Deep brain stimulation electrodes in epilepsy patients are implanted under general anesthesia. The type and depth of anesthesia might interfere with microelectrode ecordings. Here, we describe our experience of a patient who underwent deep brain stimulation surgery under general anesthesia with sevoflurane, a volatile anesthetic, and its effect on the microelectrode recordings. Keywords: Thalamus, Deep brain stimulation, Sevoflurane