A latex enzyme immunoassay (LEIA) for detecting IgG class antibody to rubella virus was compared with the latex agglutination test (LA) and a haemagglutination inhibition assay (HI). Of 243 sera tested, four discrepant results were observed among all three techniques, corresponding to borderline values. Except for one sample containing specific IgM class antibody, the difference between quantitative results from each pair of tests was always within a value corresponding to two doubling dilutions and was considered to have acceptable variation. The LEIA technique allowed 10 seroconversions to be detected, as determined by the other techniques. The LEIA required a single 1 in 8 sample dilution, took 30 minutes, and provided a useful alternative assay for the quantitation of rubella antibodies.