In this restrospective study we review the clinical features of patients with the sicca syndrome in the presence and absence of rheumatoid arthritis. All patients were followed at the National Institutes of Health for at least five years after the diagnosis of sicca syndrome was established. Twenty-two patients had sicca syndrome alone, and 21 patients had definite rheumatoid arthritis and the sicca syndrome. Rheumatoid arthritis tended to precede the developement of sicca syndrome. The mean age at diagnosis of sicca syndrome is the same in both groups. No significant differences in serum innumoglobulins, the third component of complement (C3), rheumatoid factor titer and salivary histopathology were found. However, the clinical features were quite distinct. Patients with sicca syndrome alone had a significantly greater frequency of recurrent parotitis, Raynaud's phenomenon, purpura, lymphadenopathy, myositis and renal involvement. The clinical characteristics of these two groups coupled with the known serologic and genetic differences suggest that sicca syndrome alone is a distinct pathologic entity.