Endocervical (120) and endourethral (104) swabs collected from patients attending the Gynaecological OPD and STD Clinic of a Hospital, in north India were subjected to the chlamydiazyme test to detect C. trachomatis antigen. This antigen was detected in 25 per cent (30 of 120) of cervical and 20.19 per cent (21 of 104) of urethral specimens. Of the 51 antigen positive cases, 30 (58.8%) presented with the clinical picture of cervicitis, 11 (21.5%) with urethritis, 6 (11.7%) were cases of primary infertility and 4 (7.8%) were healthy controls. The association of C. trachomatis and other sexually manifested microorganisms (Mycoplasma hominis, Ureaplasma urealyticum and Gardnerella vaginalis) was found more commonly in patients of cervicitis, especially those who were C. trachomatis antigen positive.