Abstract. Diacylglycerol kinase (DGK) is an enzyme that converts diacylglycerol to phosphatidic acid. To date, 10 isoforms of DGKs (a, b, g, d, e, z, h, q, i, and k) have been identified in mammals, and these DGKs show characteristic expression patterns and roles. The expression levels of DGKs are comparatively higher in the central nervous system than in other organs and may play several important roles in regulating higher brain functions. Currently, many studies have been performed to reveal the roles of DGKs by knocking down or overexpression of DGKs in vitro. Additionally, knockout or overexpression mice of several DGKs have been generated, and phenotypes of these mice have been studied. In this review, we discuss the roles of DGKs in the central nervous system based on recent findings in genetic models.