Cell surface glycoconjugates are believed to play an important role in cell-cell interactions during development of CNS pathways. In order to identify developmentally regulated glycoconjugates in the nervous system, monoclonal antibodies were raised and selected for reactivity with carbohydrate antigens. Three monoclonal antibodies were identified, each of which reacts with a defined carbohydrate epitope and reveals a unique pattern of immunoreactivity within the olfactory sensory epithelia, vomeronasal and olfactory nerves and their terminal regions in rats. Antibody CC1 reacts with a globoside-like glycolipid which contains a terminal N-acetylgalactosamine residue. CC1-immunoreactivity is present in just the vomeronasal organ, vomeronasal nerve and in the rostral half of the accessory olfactory bulb. Antibody CC2 reacts with a complex glycolipid which contains a branched chain oligosaccharide terminating with alpha-galactose and alpha-fucose. CC2-immunoreactivity is seen throughout the vomeronasal organ, in dorsomedial regions of the olfactory sensory epithelia, in the vomeronasal and olfactory nerves, the 1B2-immunoreactivity is highest at the luminal surfaces of receptor cells throughout the vomeronasal organ in portions of the olfactory sensory epithelia. 1B2 is also expressed on the surface of a subset of receptor cell bodies, their dendrites and the proximal region of their axons in dorsomedial regions of the main olfactory epithelium.