There is a growing appreciation that a subset of patients with primary Sjögren's syndrome (SS) also may develop a spectrum of central nervous system (CNS) complications. This article defines SS and its significance; discusses CNS, peripheral nervous system, and muscular complications of SS; identifies those areas in general or internal medicine in which SS patients with potential neurologic complications may present; describes those neurologic disorders that SS may mimic; places into perspective the controversy regarding the frequency and significance of CNS-SS; and extends our observations on the immunopathogenesis of neurologic complications in SS.