Résumé : This report illustrates the usefulness and safety of very early hemispherotomy in an infant with Ohtahara syndrome (OS) secondary to left parieto-occipital megalencephaly. It provides evidence that surgical intervention might provide promising results in selected cases, and that young age is not a contraindication for this type of surgery. © 2005 BEA Trading Ltd. Published by Elsevier Ltd. All rights reserved.