SUMMARY Peripheral nerves in five patients with rheumatoid neuropathy were examined electrophysiologically and by sural nerve biopsy. There was close correlation between the clinical severity of the disease and the degree of nerve damage found histologically and by EMG. Group 1 patients with a mild distal sensory neuropathy showed varying degrees of axonal degeneration in the large myelinated fibres and some segmental demyelination. Group 2 patients with a severe, rapidly progressive sensori-motor neuropathy had extensive loss of myelinated fibres. In one case all the large fibres had degenerated. The second case had lost both large and small myelinated fibres together with many of the non-myelinated axons. The major nerve damage in both groups appeared to be axonal degeneration but some segmental demyelination was detected. Occlusive vascular disease in the vasa nervorum was considered to be the major cause of the nerve damage. Chamberlain and Bruckner (1970) GROUP 1 A patchy glove and stocking hypoaesthesia and hypoalgesia is characteristic of this group; it is approximately symmetrical, affecting the feet more often than the hands. The onset is insidious, unobtrusive, and often associated with relatively benign rheumatoid arthritis. The sex ratio is that of rheumatoid disease; with nodules and periarticular erosions frequently present. The arthritis in most patients is seropositive, the Rose's titre being only moderate. CASE 1 I.B. is a 70-year-old housewife with a 20-year history of rheumatoid arthritis. Her arthritis is seronegative, erosive, and anodular; there is typical multiple joint involvement.Mrs B. first developed paraesthesiae and hypoalgesia in the hands six years ago; the symptoms gradually increased and now involve the lower limbs. Hypoaesthesia and hypoalgesia are present on the dorsal surface of the right hallux, left hallux, and left second toe; there are sensory changes in the fingers of both hands, but the palmar aspect of the left fourth finger and the dorsal surface of the left thumb are spared. Some sensory loss can be detected in the dorsum of the right hand. The area involved has extended slightly during the last year despite bilateral carpal tunnel decompression in 1966. Although