BACKGROUND: Involvement of the peripheral nervous system in patients with primary Sjogren's syndrome (SS) has been reported, but its prevalence in neurologically asymptomatic patients is not well known. OBJECTIVE: To assess clinical and neurophysiological features of the peripheral nervous system in patients with primary SS. PATIENTS AND METHODS: 39 (38 female) consecutive patients with primary SS, aged 20-81 years (mean 50), with a disease duration of 1-30 years (mean 8) were studied. The peripheral nervous system was evaluated by a questionnaire, physical examination, quantified sensory neurological examination, and neurophysiological measurements (nerve conduction studies). To assess autonomic cardiovascular function an orthostatic challenge test, a Valsalva manoeuvre, a forced respiration test, and pupillography were done. RESULTS: Abnormalities as indicated in the questionnaire were found in 8/39 (21%) patients, while an abnormal neurological examination was found in 7/39 (18%) patients. Abnormalities in quantified sensory neurological examination were found in 22/38 (58%) patients. In 9/39 (23%) patients, neurophysiological signs compatible with a sensory polyneuropathy were found. No differences were found in the autonomic test results, disease duration, serological parameters, or erythrocyte sedimentation rate between the patients with primary SS with and those without evidence of peripheral nervous involvement. CONCLUSION: Subclinical abnormalities of the peripheral nervous system may occur in patients with primary SS selected from a department of rheumatology, but clinically relevant involvement of the peripheral nervous system in this patient group is rare.