To investigate the central organization of efferent neurons innervating the rectal and vesical smooth muscles and the sphincteric striated muscles in the cat, horseradish peroxidase (HRP) was injected into each of these structures and retrogradely labeled neurons were identified in the sacral spinal cord. Following HRP injections into these smooth muscle structures, labeled neurons were found in the intermediolateral and intermediolateral cell columns, the cell group X of Onuf and the nucleus myoleioticus medialis of the sacral cord. HRP injections into the external anal sphincter and bulbospongiosus muscles showed labeled neurons in the cell group X of Onuf and some in the nucleus myoleioticus medialis.