Although peripheral nervous system disease is a well-established complication of primary Sjögren's syndrome (SS), until relatively recently little attention has been focused on the central nervous system (CNS) complications of this disorder. The observations discussed in this article pertain to patients with primary SS in whom the presence of a second connective tissue disorder and other etiologies for neurologic disease have been rigorously excluded. In this article, the growing clinical spectrum of CNS manifestations, neurodiagnostic techniques, serologic analyses, and immunogenetic markers associated with this disorder are reviewed.