The distribution of the neural cell adhesion molecule (N-CAM) in the taste buds of adult and developing mice was studied by use of an immunocytochemical technique. In adult mice, nerve fibers and some elongated taste bud cells reacted with anti-N-CAM antibody. Immunoelectron microscopic observation showed that only type-III (gustatory) cells, which have afferent synaptic contacts with the nerves, were N-CAM positive in the taste buds. At day 0 after birth, taste buds of the developing mice first appeared in the circumvallate papillae, and N-CAM positive cells, which corresponded to type-III cells having afferent synapses, were found. This result suggests that N-CAM is involved in formation of the synaptic contacts between type-III cells and nerves in the taste buds.