Aim: The main aim of the study was to estimate the frequency of CT infection in pregnant women, the presence of inflammatory symptoms in Pap-smears, abnormal bacterial status of the vagina and the risk of preterm delivery. Material and methods: The study was conducted between the years 2005 and 2007 on hospitalized women in The Clinic of High Risk Pregnancy. The first group consisted of 200 pregnant women in II trimester and the second of 200 pregnant women in III trimester of pregnancy. In case of each patient the indication for hospitalization was as increased risk of preterm delivery. The Pap-smears, bacterial smear and immunochromatographic test for CT were done on the first day of the treatment from the border line of the cervical epithelium. The immunochromatographic method, despite its low specificity, lower than PCR (polymerase chain reaction), is useful because of low costs, simplicity of the method and ease of the diagnosis. In case of positive immunochromatographic bCt test, PCR CT analysis should be conducted to make sure the diagnosis is correct. The Pap-smear result suggesting inflammatory process of dysplastic changes was the reason for local antibacterial btreatment after which a control smear was done. Bacterial analysis done from external ostium showed pathogenic and cohabitants bacteria and resistance to antibiotics. The written consent for the study was obtained. Results: In the group of pregnant women there were no pathological – alert bacteria smears. In the second group the alert bacteria was found in 3 cases (1,5). In 32% of the first group in 27% of cases inflammatory changes in Pap-smears were found. No positive result of CT was found in either of the groups. The symptoms of preterm delivery were found in 78% members of the first group and in 84% cases of the second group. Preterm delivery occurred in 4 cases in the first group (2%) and 6 cases in the second group (3%). Conclusions: 1 In analyzed groups of pregnant women the CT infection was excluded. 2. The inflammatory symptoms on uterine cervix were not connected with CT infection.