Chlamydial infection is an important cause of genital tract disease in women and is often silent. Collection, storage and transportation of specimens required for culture pose problems which have made studies difficult and diagnosis impractical outside hospitals or sexually transmitted disease clinics.The direct monoclonal antibody test (MicroTrak, Syva) for detecting chlamydiae is comparable with the traditional culture method in sensitivity and specificity. The test requires only the preparation of a smear on a slide, making it convenient for use in general practice. The feasibility of using this procedure in an inner city practice was demonstrated in tests on 188 women who required pelvic examination. Of 169 women from whom valid specimens were obtained 18 (10.7%) were found to have a chlamydial infection. Only three of the infected women were asymptomatic and the organisms were associated particularly with dysuria. The value of the test in comparison with other procedures currently available for detecting chlamydiae is emphasized.