Cytokines are proteins best known for facilitating communication between cells of the immune system. Many of these same cytokines also act as signaling molecules between the cells in nonimmune organs such as the nervous system. As a consequence of this dual role, cytokines induced in response to maternal infection or certain perinatal complications can profoundly impact nervous system development. The neurodevelopmental impact of modulating the signaling of individual cytokines is being investigated in animal models. In this review, we outline these studies and discuss how their findings set the foundation for ongoing and future work aimed at understanding how cytokines induced normally and pathologically during critical stages of fetal development influence nervous system function and behavior later in life.