Autopsy in a patient with severe hyponatremia showed central pontine myelinolysis. Review of our patients with central pontine myelinolysis and those described in the English literature to data disclosed that 61 percent had documented hyponatremia. While the exact mechanism involving hyponatremia and central pontine myelinolysis cannot be defined, a circumstantial relationship is apparent. The purpose of this paper is to emphasize this relationship and to suggest that the possibility of central pontine myelinolysis be considered in any patient with hyponatremia and neurologic dysfunction.