Pleurisy with or without effusion has not been considered to be associated with primary Sjögren's syndrome (SS), but rather to represent a manifestation of the underlying disorder, usually rheumatoid arthritis in secondary SS. We describe a patient with primary SS who presented with pleural effusions (PE) as an initial manifestation. Serological studies of paired serum and PE specimens demonstrated the occurrence of local immune reactions in the pleura, including the production of rheumatoid factor and anti-SS-A antibody, the formation of immune complexes, and activation of complement. In addition, the analysis of T cell receptor beta-chain variable (V beta) regions in the PE revealed the overexpression of a number of V beta gene products, including V beta 2 and V beta 13 that have previously been shown to be over-represented in the salivary glands of patients with SS. Thus, our report not only calls for an awareness of pleurisy as an extraglandular manifestation of primary SS, but suggests that a common biased T cell response might play a critical role in the pathogenesis of the glandular as well as extraglandular manifestations.