A case of Dejerine-Sottas hypertrophic neuritis is reported. The patient, a 45-year-old male, suffered from chronic hypertrophic polyneuropathy, abnormal pupils, fasciculations, tremor, back pain, impotence, sphincter disorders, cramps, and lightning pains in the lower extremities. Besides extensive subarachnoid block, there was X-ray evidence of enlargement of the bony spinal canal with scalloping of the lumbar vertebrae. Surgical exploration showed these abnormalities to be due to extreme hypertrophy of the cauda equina. Histologic findings in peripheral nerve and lumbar root biopsies were typical of hypertrophic neuropathy of the onion bulb type. Vertebral changes secondary to hypertrophied nerve roots appear not to have been described before in hypertrophic neuritis; however, knowledge of their possible occurrence may be of practical importance in the management of similar future cases. A simple way of visualizing enlarged peripheral nerves is briefly described.