Valproic acid (VPA) was first synthesized in the United States (Burton, 1882) and was used worldwide for 80 years as an organic solvent. Its unexpected antiepileptic activity was discovered 20 years ago in Grenoble, France (Meunier et al., 1963; Carraz et al., 1964). The aim of this work is to report the progressive evolution of ideas and the clinical approach to the treatment of epilepsy with sodium valproate (Na VPA) and VPA, according to published open trials and to our own unpublished data.