Symptoms suggestive of a lower genital tract infection (LGTI) are common complaints in women who consult gynecologists. Sexually transmitted microorganisms, such as Chlamydia traclwtnalis, Neisseria gonorrlweae, and Trichomonas vaginalix, are responsible for a substantial proportion of LGTI. This study was performed to establish the frequency of LGTI caused by C trachomaiis in women attending a gynecologic outpatient clinic. Of 170 women with LGTI,32.9% harbored one or more of these organisms: C trachomatis was found in 19.3%, Ngonorrhoeae in 4.7%, and T vaginalis in 25.9%. The results of the isolation studies were correlated with clinical signs and symptoms. In women under 25 years of age, chlamydial cervicitis was found significantly more often in users of oral contraceptives than in nonusers. In women not taking such drugs, cervical erosion was found more often in Chlamydia-positive than Chlaimydia-negative women. Since clinical examination failed to reveal any characteristic signs in cases of chlamydial infection, it was not possible to distinguish a chlamydial from a gonococcal infection. This study also reports the successful treatment of 15 women affected by chlamydial cervicitis with doxycycline or trimethoprim sulphamcthoxazole.