An elderly man presented with signs and symptoms indicating a rapidly progressive central and peripheral nervous system disease, which led to death within 3 months. The pathologic picture was that of a "paraneoplastic" encephalomyelitis and neuritis, but no cancer could be found. Supratentorial predilection for the limbic structures correlated well with an observed limbic dementia. Arguments favoring a direct toxic or metabolic effect of cancer as a cause for this syndrome are less convincing in view of this report.