Complement fixation (CF), immunofluorescence (IF) and immunoenzymatic (ELISA) tests by commercial sources were compared, for routine laboratory detection of cytomegalovirus IgG antibodies, on 120 serum samples from normal pregnant females. IF and ELISA were comparable in terms of specificity and sensitivity, but in our opinion ELISA showed some advantages with regard to need for facilities and trained personnel. CF could not detect some of low titer positive sera, so it can not be suggested where it is critical to know a previous contact with the virus, as in blood donors or transplant donors and recipients.