Nerve cell counts of the lateral horns of the spinal cord were performed in 15 cases of multiple system atrophy (MSA) and three age-and sexmatched controls. The patients with MSA were comprised of eight with severe postural hypotension, three with orthostatic hypotension and little or no disability and four without any signs of autonomic failure. All cases of MSA had lost more than half their lateral horn cells but nerve cell loss could not be correlated with the degree of dysautonomia. These results confirm the involvement of the intermediolateral columns of the spinal cord in MSA. However, the lack of correlation between cell loss and severity of autonomic failure in our cases, suggests that lesions of other sites, such as sympathetic ganglia or the dorsal vagal nuclei, are also implicated in dysautonomia.