A 38-year-old woman suffering from primary Sjögren's syndrome displayed a neurologic picture consisting of left tonic pupil, generalized tendon areflexia and left-sided hypohidrosis. Electrophysiological and pathological studies suggested a mild degree of peripheral nerve involvement. Moderate loss of large myelinated fibres and obliteration of small endoneurial vessels were seen in the sural nerve biopsy. Sympathetic skin response was absent and alterations of unmyelinated nerve fibres were found. A prevalently autonomic neuropathy with tonic pupils may represent a characteristic picture in the spectrum of peripheral nerve involvement in Sjögren's syndrome. Other similar cases reported in the literature are reviewed.