A combination of multiple sclerosis (MS) and hypertrophic demyelinating neuropathy has been reported in a few autopsy studies. We are reporting a unique case of such a combination, which was proved by the sural nerve biopsy. A patient with classical MS on history and findings had areflexia and sensory abnormalities in stocking distribution. The nerve conduction study showed marked abnormalities indicative of demyelinating neuropathy, and sural nerve biopsy was typical of hypertrophic demyelinating neuropathy. Copyright © 1983 John Wiley & Sons, Inc.