The aim of the study was to provide a survey and generalization of literature data on the epidemiological situation of Chlamydia trachomatis infection in various countries, preventive screenings and risk factors of the infection. We performed a survey of articles published during 1998-2005 and selected from bibliographical medical search databases presenting data on the prevalence of Chlamydia trachomatis and the main risk factors for this sexually transmitted infection. Chlamydial infection is the most common among sexually transmitted genital infections worldwide. It has been found that the main risk factors for Chlamydia trachomatis infection are age, irregular and/or accidental sexual relationships and change of sexual partners, failure to use or erratic use of barrier contraception during intercourse, and insufficient knowledge about sexual life and care for one's sexual health. Most countries do not have national preventive screening programs or exhaustive information about the prevalence of Chlamydia trachomatis infection. The comparison of the prevalence and incidence of Chlamydia trachomatis infection among different countries is complicated due to the different diagnostic methods and sample selection techniques applied; however, in order to decrease the prevalence of chlamydial infection and its impact on the reproductive health of the society, significant attention should be paid to sexual education, preventive screening of people in high-risk groups, as well as to early diagnostics and timely treatment.