Background. Lymphogranuloma venereum (LGV) is a sexually transmitted infection (STI), which is caused by L1-L3 serovars of Chlamydia trachomatis (C. trachomatis-LGV). Clinically, LGV often manifests behind the mask of proctocolitis related to inflammatory bowel diseases, and men who have sex with men (MSM) are susceptible to infection. Cases of LGV in the Moscow region have been registered since 2018. Timely molecular diagnosis of LGV can reduce the incidence of such socially significant diseases as HIV, syphilis and hepatitis C among MSM, and assessment of patients’ behavioral risks in the history taking allows to suspect this diagnosis in men referring with specific clinical mani-festations to coloproctologists, gastroenterologists or dermatovenereologists. Objective. To assess the prevalence of infection caused by L1-L3 and D-K serovars of C. trachomatis among MSM in the Moscow region, to study comparatively the socio-behavioral features of patients. Material and methods. During this study, 855 men, residents of Moscow, with inflammatory diseases of the rectum and anal canal, who vis-ited coloproctologist were screened. Patients underwent: proctological examination, testing for the presence of STIs causative agents’ DNA with a real-time polymerase chain reaction, serological assay for HIV, syphilis and viral hepatitis. Socio-behavioral characteristics were evaluated according to the data obtained from the questionnaire. Results. LGV has been revealed in 279 persons, urogenital chlamydia infection of anorectal localization — in 92 persons. All patients with LGV belonged to MSM, significantly more often had group sex compared to the patients with urogenital chlamydia infection, had more than 5 partners in 6 months before health encounter, history of syphilis as well as were HIV-infected. Conclusion. The prevalence of infection caused by L1-L3 and D-K serovars of C. trachomatis has been evaluated among MSM in the Moscow region, socio-behavioral features of patients seeking coloproctological care have been studied comparatively. © 2025, Media Sphera Publishing Group. All rights reserved.