Stereo electroencephalography (EEG) has become the predominant method across the world to invasively explore patients with focal epilepsy who are potential candidates for resective surgery. This required many epilepsy centers to introduce major workflow adaptations, investment in surgical and imaging technologies, and seek training in placement and interpretation of depth electrodes recordings. It became evident that a comprehensive, practical textbook outlining the different steps and nuances of the methodology was missing. This book covers all practical aspects of stereo EEG and is a quintessential staple for anybody learning and working in the field of epilepsy surgery, including adult and pediatric epileptologists and neurophysiologists, functional neurosurgeons, technologists, and trainees in these areas. The book is a complete and practical guide to thinking and doing stereoelectroencephalography (SEEG) which will be a solid reference to practitioners around the world. Almost all chapters feature illustrative cases to explain specific aspects and key concepts of the SEEG methodology. The section covering the practical approach to specific epilepsy syndromes includes voice-over slide presentations demonstrating the process of a systematic patient discussion, hypothesis generation, and electrode planning followed by data interpretation and delineation of surgical resection. The book starts with the historical background and principles of stereo EEG and discusses the role of the noninvasive evaluation and patient selection. It describes technical aspects of electrodes, multimodal data coregistration, and guidelines for invasive monitoring. The book then presents the conceptual framework of stereo EEG followed by surgical aspects of stereo EEG electrode placement covering robotic and frame-based approaches, specific pediatric aspects, and potential complications. It describes data interpretation of physiologic, interictal, and ictal epileptic activity, and outlines conceptual and methodological aspects of electrical stimulation mapping. The book ends with discussing surgical procedures to remove the epileptogenic zone and a review of seizure and cognitive outcome with stereo EEG.