**Abstract**

*Chlamydia trachomatis* is known as the most common bacterial infection agent to pass with sexual transition. This microorganism is an obligatory intracellular parasite. A variety of infections are caused by *C. trachomatis*, including trachoma, pneumonias in newborns, genital and urinary tract infections, and lymphogranuloma venereum (LGV), which is caused by LGV strains. The diagnosis of *Chlamydia trachomatis* can be made by cultures and isolations, antigens and antibodies (direct fluorescence, enzyme immunoassays), hybridization, or polymerase chain reaction (PCR). Each year, infection and diagnosis rates increase in the developed world. Since *Chlamydia* is mostly asymptomatic, screening, and treatment are a key to detecting cases. Polymerase chain reaction (PCR), ligase chain reaction (LCR), and nucleic acid sequence-based amplification (NASBAa) molecular methods can be used for the detection, low concentration, quantification, and identification of organisms. While the traditional PCR method confirms its existence, it can quantify real-time PCR (RT-PCR). This method (RT-PCR) may have low sensitivity among variants of the same species. Also, PCR scans, which receive urine service, offer great advantages. PCR from initial void urine (FVU) samples is highly sensitive in detecting the organism. Urine Chlamydia screenings are more acceptable in large populations and asymptomatic detections.

**Keywords:** *Chlamydia*, molecular identification, characterization, chlamydia trachomatis, chlamydia diagnosis
