The processes of neurulation, patterning, neuronal specification, and synaptogenesis, as well as the functional dynamics of neurotransmission, are governed by the coordinated actions of products from a wide array of genes. Neurodevelopmental etiology of schizophrenia is suggested by neuroimaging and postmortem studies revealing significant and replicated lateral ventricular enlargement, hippocampal and gray matter deficits, and cellular disarray, independent of duration of the illness and antipsychotic treatment. This chapter provides an overview of the major mechanisms involved in the development of the mammalian central nervous system (CNS), with specific reference to the identity and patterning of genes that are known to regulate the developmental phases. This pattern of gene expression is related to the etiology of schizophrenia through evidence provided by genetic, postmortem, imaging, electrophysiological, and behavioral investigations of the disorder.