Viral infection has often been suggested as a possible cause of Sjögren's syndrome or chronic lymphocytic sialadenitis, and Epstein-Barr virus has been found in the salivary glands of patients with this condition. After we had noted Sjögren's syndrome in several patients infected with hepatitis C virus (HCV), a virus also excreted in saliva, we set up a prospective study to investigate the association of chronic lymphocytic sialadenitis, with or without symptoms, to chronic HCV liver disease. The histological appearances of labial salivary glands in patients with proven HCV hepatitis or cirrhosis were compared with those in dead controls. Histological changes characteristic of Sjögren's syndrome were significantly more common in HCV-infected patients (16 of 28, 57%) compared with controls (1 of 20, 5%). Focal lymphocytic sialadenitis characteristic of Sjögren's syndrome (though only 10 patients had xerostomia and none complained of xerophthalmia) appears to be common in patients with chronic HCV liver disease; if this association is confirmed, identification of the underlying mechanism may improve our understanding of both disorders.