In five patients with Fabry's disease, the distribution of neurons in the spinal cord affected by lipid storage was investigated. Neurons ballooned by lipid storage were located mainly in the thoracolumbar and mid-sacral regions. In the former, they were located exclusively in the intermediolateral nucleus from the first thoracic (or eighth cervical) through the first or second lumbar segments. In the mid-sacral region they were located not only in the intermediolateral nucleus but also in the intermedioventral (Onuf's) nucleus and in the intermediate region of the ventral horn. The affected neurons in the sacral cord are also assumed to be autonomic neurons judging from the selective involvement of known autonomic neurons in the thoracolumbar segments. Based on the distribution of these neurons, it is concluded that autonomic neurons in the human sacral cord form a cell column which differs topographically from that in the thoracolumbar segments. The cell column begins rostrally at the ventral margin of the ventral horn in the second sacral segment as Onuf's nucleus and extends caudally in a dorsolateral direction along the intermediate region to the intermediolateral nucleus in the fourth sacral segment, which forms the caudal part of the cell column.