Despite the apparent uniformity in cellular composition of the mammalian cerebellar cortex, a complex topography is revealed by several expression patterns. Zebrin II, a polypeptide antigen identified as aldolase C, is one such marker which, in several species of mammals, is restricted to a subset of Purkinje cells that are clustered together to form a symmetrical and reproducible array of zones and stripes. In rodents the cerebellar cortex is divided into four transverse zones--anterior, central, posterior, and nodular. Each transverse zone is further subdivided mediolaterally into an array of parasagittal stripes. The similar zone and stripe organization partitions the hemispheres. Based upon a novel whole mount immunohistochemical staining procedure, we have now identified homologous zones and stripes in the feline cerebellum. In the cat cerebellum the somata of most Purkinje cells express zebrin II but parasagittal stripes may still be delineated owing to the alternating high and low zebrin II expression levels in the dendritic arbors. As in rodents, the cat cerebellum consists of four transverse zones with each zone subdivided into a unique combination of zebrin II parasagittal stripes, suggesting that a common architecture underlies the organization of the mammalian cerebellum.