The Drosophila Delta gene and its vertebrate homologues are ligands for the Notch receptor and are involved in a variety of developmental processes, including neurogenesis, boundary formation, and axon guidance. This study deals with the ectodermal expression and function of X-Delta-2 during early Xenopus laevis development. X-Delta-2 is expressed, from early neurula stages on, throughout the central nervous system (CNS; forebrain, eyes, midbrain, hindbrain, and spinal cord) and in the majority of the cranial placodes. Loss of function experiments using a morpholino knockdown approach revealed that X-Delta-2 is necessary for hindbrain segmentation and the correct specification of the anterior CNS. X-Delta-2 also seems to be important in the determination of the size of the eyes. Furthermore, our results suggest that X-Delta-2 is involved in the migration of the cranial placodes cells, as well the migration of the cranial neural crest cells. Developmental Dynamics 235:802–810, 2006. © 2006 Wiley-Liss, Inc.