BACKGROUND In this study we aimed to evaluate the effect of intrauterine devices (IUDs) on cervico-vaginal colonization. METHODS Cervico-vaginal samples of 96 patients with vaginal discharge were included in the study. Microscopic evaluation, bacteriological and fungal culture, and antigen testing for Chlamydia trachomatis using an immunochromatographic test method were performed. RESULTS Trichomonas vaginalis was not detected by wet mount examination. Gram smear revealed that seven patients (7.3%) had Candida spp. and five (5.2%) had clue cell. Of the 96 swabs tested for conventional culture, pathogenic microorganisms were isolated from 24 patients. While Neisseria gonorrhoeae was not found in any of the sample, five (5.2%) were positive for Gardnerella vaginalis. Five (5.2%) were positive for C. trachomatis antigen, while three positivity only for C. trachomatis antigen, one had G. vaginalis additionally, and the other had a mixed infection. Chlamydial antigen positivity was higher among women over 30 years of age (p = 0.157). Increase in polymorphonuclear leukocytes (PNL) was detected 40% and 35.2% of samples, positive and negative, for chlamydial antigen, respectively (p = 1.000). Among IUD+ cases, increase in PNL, fungal elements,  E. coli and Gram-positive bacteria and decrease in Lactobacillus spp. were observed, compared to IUD-cases. No statistically significant relationship was detected between IUD and chlamydial antigen with the reported rates of 4.8% and 5.6% for IUD+ or IUD-, respectively (p > 0.05). CONCLUSIONS Statistically significant relationship was not detected between IUD and cervico-vaginal colonization. More comprehensive studies using specific test methods should be conducted to better understand the relationship.