Endocervical smears from 200 female sex workers were tested for Chlamydia trachomatis infection using the Abbott and Murex enzyme immunoassay (EIA) kits and the standard cell culture technique to compare the performance of these tests. The Abbott test had a sensitivity, specificity, predictive value of a positive result (PVP) and predictive value of a negative result (PVN) of 83.3%, 97.8%, 78.9% and 98.3% respectively. The corresponding figures for the Murex system were 77.8%, 98.4%, 82.4% and 97.8%; and of the standard culture test were 55.6%, 100% and 95.8%. EIA tests were more sensitive but slightly less specific than cell culture in the detection of Chlamydia trachomatis cervical infection in female sex workers in Singapore.