A microparticle enzyme immunoassay (LEIA) that uses passive latex agglutination was used to detect cytomegalovirus immunoglobulin G antibodies in 495 serum samples. LEIA was in excellent concordance with latex agglutination (97%) and an enzyme-linked immunosorbent assay (98.3%). The sensitivity and specificity of LEIA compared with those of the enzyme-linked immunosorbent assay were 100 and 92.5%, respectively.