Whole saliva composition and flow rate were examined in 22 patients with systemic lupus erythematosus and compared with matched healthy controls. Significantly lowered salivary flow rate was observed in patients with systemic lupus erythematosus unrelated to the subjective complaint of xerostomia. Salivary sodium, calcium, and magnesium concentrations were significantly higher in the SLE patients with systemic lupus erythematosus, whereas potassium and total protein concentrations and amylase activity did not differ significantly from the controls. Salivary IgA and IgM levels were significantly higher in the patients than in controls. IgA, IgG, IgM, C3, C4, antinuclear antibody, and anti-DNA antibody levels were measured in serum of the patients with systemic lupus erythematosus and correlated with salivary immunoglobulins. The only significant correlation between saliva and serum was found between levels of salivary IgG and serum anti-DNA antibody. The altered salivary composition might indicate a subclinical involvement of salivary glands in the patients.