Thirty-eight consecutive patients with primary Sjögren's syndrome (SS) and 36 with suspected (15 cases) or probable to definite (21 cases) multiple sclerosis (MS) underwent thorough neuropsychiatric and rheumatological examinations in order to detect either the presence of central neurologic involvement in SS or the presence of clinical and immunologic abnormalities typical of SS in MS. The only neuropsychiatric abnormality we found in patients first recorded for primary SS was major depression in 5 cases. On the other hand, one patient with suspected MS because of mild gait ataxia and right hemiparesis fulfilled the diagnostic criteria for SS. As for serologic tests, 6 out of 21 patients with probable to definite MS and 1 out of 15 with suspected MS had low-titre antinuclear antibodies. One patient with definite MS had also circulating anti-SSA/Ro antibodies, detected by gel double diffusion, but did not develop sicca symptoms after a 2-year follow-up. In the present study, the association between SS and MS was considerably weaker than that recently reported in other studies, and might be regarded as a chance finding.