Chlamydiae are very tiny, round and gram-negative bacteria. Chlamydia trachomatis species is pathogen for humans, which causes the disease of the reproductive tract and the newborns. Chlamydia trachomatis is sexually transmitted bacteria, and its infection is manifested by intracytoplasmic inclusions in endocervical cells. C. trachomatis bacteria attacks squamous columnar epithelium that attacks not only reproductive tract, but also urinary tract, respiratory tract as well as conjunctiva. The most significant problem of Chlamydial infection is that they are typically asymptomatic, and are often unknown and untreated. Left untreated, infection can lead to complications with serious consequences such as pelvic inflammatory disease, ectopic pregnancy, infertility, pregnancy problems and neonatal complications (conjunctivitis and pneumonia) At the present time the tests of choice or the new golden standard of CT urogenital infection diagnosis are nucleic acid amplification molecular tests, because of their high sensitivity, as well as their performance feasibility in invasive and noninvasive specimens, such as self-collected vaginal swab or first urinal flow. The recommended treatment is a single-dose of azithromycin, or 1-week treatment by doxycycline (on all positive sexual partners). The present study shows that Chlamydia is less common tested in people younger than 25 years of age, only 12.4% of the total number tested for Chlamydia belong to the younger than 25 years old (987/7984). This suggests that Chlamydia testing should be promoted at the adolescent age, because in the present study it was confirmed that there were statistically significant more positive test results in the age group younger than 25 in compare to 1.56% (109/6997) in the age group older than 25 years of age. By timely diagnosis and treatment of Chlamydial infections, it is possible to prevent the development of complications and thus to preserve the reproductive health of young people and to prevent neonatal infections. Chlamydial infection diagnosis is often determined when it comes to unwanted consequences and so it is necessary to perform Chlamydial screening. Some countries already perform the Chlamydial screening as a standard preventive procedure. Screening female population younger than 25 years of age is ranked as one of the 10 most beneficial and most cost effective prevention strategies because it is less expensive than the cost of caring after the infected population.