Objective To assess the prevalence of mycoplasma genitalium （MG） in patients attending sexually transmitted disease （STD） clinic in Guangzhou， and to provide an epidemiological foundation for clinical treatment and laboratory diagnostics. Methods Utilizing real?time polymerase chain reaction （PCR）， we analyzed MG DNA in 2，749 clinical specimens collected from 2，722 outpatients in the Dermatology Hospital of Southern Medical University from July 2019 to December 2021. Concurrent testing for MG， Chlamydia trachomatis（CT）， and Neisseria gonorrhoeae （NG） was performed on 2，382 of these specimens. Patient data extracted from medical records were used to investigate the correlation between STD symptoms and MG infection. Results The investigation revealed that the overall prevalence of MG infection was 4.4 % among the sampled patients （120 out of 2，722）， with a higher prevalence in males （4.9 %， or 87 out of 1，790） compared to in females （3.5 %， or 33 out of 932）. Notably， the prevalence decreased with increasing age. The highest incidence of MG infection was observed in females aged 18 ~ 25 years （6.4 %， or 18 out of 281）， while the lowest was in males aged 46 years and above （1.5 %， or 5 out of 342）， showing a statistically significant variation across age groups （P < 0.05）. Among males with urethritis symptoms， MG positive rate was significantly higher at 7.3 % （42 out of 574）. The rate of single MG infection was prominent， accounting for 89.9 % （71 out of 79） in MG?positive male patients and 61.5 % （16 out of 26） in MG?positive female patients. Co?infection rate of MG with CT was 1.2 % in females and 0.3 % in males， indicating a significant difference （P < 0.05）. Conclusion The findings suggest a relatively high prevalence of MG infection and co?infection with CT among STD clinic attendees in Guangzhou， particularly in the younger demographic. The study underscores the need for early screening and vigilant surveillance of MG to mitigate its transmission among sexually active populations at high risk.