In a prospective study, 66 patients fulfilling the criteria of Sjögren's syndrome were evaluated from the standpoint of the presence of soluble SS-A, SS-B and RNP specific nuclear antigen antibodies. There were 25 cases of pure Sjögren's syndrome and 41 cases of this syndrome associated with a connective tissue disease. Anti SS-A antibodies were found in 10 per cent of cases and anti SS-B in 21 per cent, without there being any significant difference in prevalence between pure and associated forms of Sjögren's syndrome. Three patients simultaneously showed anti SS-A and anti SS-B antibodies, four had only anti SS-A and eleven anti SS-B. Amongst the forms associated with a connective tissue disease all of the latter were represented with an equivalent prevalence. 18 per cent of the patients had anti-RNP with a majority of associated forms of Sjögren's syndrome. In this population of 66 patients with Sjögren's syndrome, no clinical manifestation appeared to be correlated with the presence of anti SS-A and SS-B antibodies. Amongst the laboratory features, only cryoglobulins were significantly more frequent.