Epilepsy represents a considerable health care problem, and in the United States the prevalence is 500 to 800 cases per 100,000. The classification of epilepsies, seizures, and epileptic syndromes uses these categories: primary, generalized, and partial. It is the partial epilepsies where functional neuroimaging is of special interest. Partial seizures originate from one focus. The epileptic discharge may remain localized or may spread over the whole brain. In the latter case, one talks of “secondary generalization.” If partial seizures involve consciousness, they are referred to as “complex partial seizures.” In general, these originate in the medial temporal lobe. Although most epileptic patients are adequately treated with medication, a considerable number are medically intractable. A major subgroup of these patients suffer from temporal lobe epilepsy (TLE), which is commonly associated with hippocampal sclerosis. Surgical treatment in these cases has proven to be an effective means of eliminating seizures. There exist various surgical strategies. The standard procedure initially consisted of removing the anterior two thirds of the affected temporal lobe, so-called Falconer’s en bloc anterior temporal lobe resection. In Zurich, the standard operation since 1975 has been selective amygdalohippocampectomy, a procedure pioneered by Wieser and Yasargil (1). For extratemporal refractory epilepsy, surgical therapy is less often performed, although this is changing with improved methods for presurgical evaluation. In general, positron emission tomography (PET) imaging has proven to be useful in candidates for epilepsy surgery.