Vasoactive intestinal peptide (VIP) mediates important events during the development of the nervous system. VIP can stimulate neuronogenesis as well as differentiation and neurite outgrowth; it can promote the survival of neurons and assist in neuronal repair; it is also anti-inflammatory and can modulate immune responses. In addition, VIP is necessary for the normal growth and development of the early postimplantation mouse embryo during the period when the major embryonic events are neural tube formation, neuronogenesis and expansion of the vascular system. Receptors for VIP appear during early postimplantation embryogenesis in the rodent and exhibit changing localization patterns throughout the development of the brain. During embryogenesis, unregulated VIP may have major and permanent consequences on the formation of the brain and may be a participating factor in disorders of neurodevelopment. VIP has been linked to autism, Down syndrome and fetal alcohol syndrome. This paper will review the role of VIP in neurodevelopment, its known involvement in neurodevelopmental disorders and propose ways in which VIP might be of therapeutic value.