A typical case of a patient with a partial epilepsy is presented, emphasizing the delay before a correct diagnosis and the initially normal standard tests. We show how a careful analysis of seizure semiology permitted a precise identification of the focal zone within the mesial temporal lobe. This patient experienced prolonged, repeated febrile seizures in infancy suggesting the epilepsy was linked with a hippocampal sclerosis. Surgical intervention is usually effective in such cases, when MRI scans reveal a temporal lobe lesion and seizure morphology has been captured on long term video-EEG recordings. Presurgical evaluations are described, which must be made rapidly for patients with partial epilepsies resistant to two antiepileptic drugs Numerous axes of research have been developed around presurgical evaluations and we show how they improve our understanding of the pathophysiology of partial seizures.