In four patients with the Shy-Drager syndrome, detailed pathological findings in the central nervous system are described. All four patients had striatonigral degeneration, olivopontocerebellar atrophy, pyramidal tract degeneration and ventral horn cell loss. Along with the multisystem degeneration, there was widespread loss of thoracolumbar autonomic neurons, which was demonstrated by comparative cell counts of the intermediolateral horns in two of the four patients. In all four patients, autonomic nuclei of the sacral cord, particularly the Onuf's and intermediolateral nuclei, were severely affected and diffuse cell loss in the nuclei seems to account for disordered bladder, rectal and sexual functions in Shy-Drager syndrome.