One hundred female patients clinically diagnosed as pelvic inflammatory disease (PID) were studied for the presence of chlamydial infection by cytology and antigen detection. Cervical smears stained by Giemsa revealed inclusion bodies, only in 3 percent of cases. While using Immunocomb Enzyme Immunoassay (EIA) test, antigen was detected in 13% of cases, thereby showing that antigen detection is a better method than cell cytology. A significant correlation with the low socioeconomic status and younger age group was seen in patients showing presence of Chlamydia trachomatis antigen.