Sacral parasympathetic preganglionic neurons innervating the urinary bladder were labelled by applying horseradish peroxidase (HRP) to branches of the pelvic nerve at the neck of the bladder. Bladder preganglionic cells were located primarily in the intermediolateral grey matter of sacral cord segments 1, 2 and 3 and extended from the ventral end of the central canal to the inferior margin of the dorsal horn. Dendrites extended into the dorsolateral funiculus, toward the lateral edge of the dorsal horn, medially beneath the dorsal horn and ventrally within the nucleus. Although a small number of cells were found medially beneath the dorsal horn, it is concluded that the majority of bladder preganglionic neurons occupy a lateral position within the sacral parasympathetic nucleus.