Imprinted genes are an epigenetically regulated class of genes that are preferentially expressed from one parental allele. A number of these genes are crucial for placental function and embryonic growth in mice and humans. Disruption of imprinted genes is also associated with several neurodevelopmental disorders, although the role of genomic imprinting in the brain remains largely unresolved. In this article, we describe current knowledge on the various epigenetic mechanisms that can drive monoallelic expression, provide examples of imprinted genes with relevant function in the brain and discuss imprinted gene deregulation in various neurodevelopmental disorders. Continued efforts in this field will be necessary in order to fully appreciate how the modulation of imprinted gene expression is essential to achieve normal development, and therefore function, of the mammalian nervous system.