We evaluated prospectively twenty-two subjective sicca features in seventeen patients with Sjögren's syndrome (SS) including six patients with primary SS twice at a six-year interval. In the second evaluation in 1986, the frequency of sicca symptoms was increased for most items, and the mean number of positive symptoms was also increased in the patients compared with the results in 1980. In the first evaluation, three patients lacked any sicca symptoms, and were considered as subclinical SS. Sicca symptoms developed in all three of these patients later. A positive correlation between the number of sicca symptoms and the patients' age was also reconfirmed by the present study. Changes in sicca symptoms between the two evaluations were not correlated with objective findings of exocrine gland involvement determined at the time of diagnosis of SS. The lacrimal or salivary secretion and sialographic findings determined serially were relatively stable during whole observation period, except in some patients. The results indicate that both the symptoms and objective findings of glandular involvement progress very slowly in SS, although patients with subclinical disease eventually develop clinical SS.