We investigated the expression of the three known Slit-Robo GTPase activating protein (srGAP) genes in the developing murine nervous system using in situ hybridization. The three genes are expressed during embryonic and early postnatal development in the murine nervous system, showing a distinct pattern of expression in the olfactory system, the eye, forebrain and midbrain structures, the cerebellum, the spinal cord, and dorsal root ganglia, which we discuss in relation to Slit-Robo expression patterns and signaling pathways. We also report srGAP2 expression in zones of neuronal differentiation and srGAP3 in ventricular zones of neurogenesis in many different tissues of the central nervous system (CNS). Compared to srGAP2 and srGAP3, the onset of srGAP1 expression is later in most CNS tissues. We propose that these differences in expression point to functional differences between these three genes in the development of neural tissues. J. Comp. Neurol. 513:224–236, 2009. © 2009 Wiley-Liss, Inc.