Sjogren's syndrome (SS) is a systemic autoimmune disease that predominantly affects women. SS is characterized by lymphocytic infiltration of lacrimal and salivary glands leading to secretory function loss, and the symptoms of dry eyes and dry mouth. After bone marrow transplantation, most patients with chronic graft versus host disease (GVHD) develop symptoms of oral dryness and salivary gland lymphocytic infiltrates indistinguishable from SS. Thalidomide has not been studied as a treatment for Sjogren's syndrome, but pilot studies suggest that it may be beneficial in the treatment of a number of autoimmune diseases including rheumatoid arthritis, systemic lupus erythematosus, and various skin disorders, as well as in the treatment of chronic graft versus host disease. Major adverse effects of thalidomide include teratogenicity, neuropathy and sedation. The study is a 12 week randomized, double-blinded, pilot clinical trial designed to screen for potential efficacy and to evaluate the safety and potential adverse effects of 300 mg thalidomide daily compared with placebo in 28 patients with primary SS (PSS).