Concentration of IgA was measured in saliva samples from 23 healthy adults by solid phase radioimmunoassay (RIA), rocket Immunoelectrophoresis (IEF) and single gradial immunodiffusion (SRID). In preliminary experiments it was found that all three methods gave too low values of salivary IgA unless the samples were reduced with dithiothreitol.After such reduction the mean concentrations of IgA in whole saliva were 100 mg/l (log mean 2.01±0.22) measured with RIA, 90 mg/l (log mean 1.95±0.18) measured with IEF and 120 mg/l (log mean 2.06±0.19) measured with SRID.