We have documented the initial clinical features of 100 patients with primary Sjögren's syndrome (SS) together with the results of their baseline investigations. The evolution of the disease in these patients has been followed for a median of 34 months (range 3-84 months). The majority of patients were females aged 40-60 years, and common clinical features included eye symptoms (100%), xerostomia (100%), polyarthralgia (94%), Raynaud's phenomenon (81%) and salivary gland swelling (47%). Thyroid disease was relatively common (14%) while other endocrine disease was rare. Four patients died during follow-up, and three cases of lymphoma were detected. Other serious complications included pericarditis (10%), pleuroparenchymal lung disease (9%), renal tubular acidosis (3%) and cerebrovascular accidents (2%). The presence of anti-Ro antibodies identifies patients with more severe systemic disease. Spontaneous improvement occurred in 12 patients, while steroids were required for specific complications in 18. Overall, although lymphoma was found to excess in our group, the high mortality reported with primary SS elsewhere was not seen.