Dravet syndrome is a rare and severe type of epilepsy. "Severe myoclonic epilepsy in infancy" was first described in 1978 by Charlotte Dravet, who observed common features: onset in the first year of life, fever sensitivity, multiple seizure types, often including myoclonic seizures, and cognitive deterioration. Subsequent descriptions contributed to delineating a newly recognised epilepsy syndrome. Renzo Guerrini contributed to the knowledge of the genetic basis and response to anti epileptic drugs of Dravet syndrome. New molecules have emerged, and studies on cognitive development have qualified the impairment. Families' associations have also contributed to a better knowledge of the syndrome. Charlotte Dravet and Renzo Guerrini present here the state of current knowledge about this epilepsy type. This book aims to provide more information on the syndrome to those neurologists, child neurologists, and pediatricians confronted with infants, children and adults who either have or are suspected to have Dravet syndrome. Even if significant gaps in our understanding of the syndrome remain, the authors hope this contribution may assist in the understanding of the disease and optimization of treatments.