BACKGROUND: The incidence of sexually transmitted infections (STIs) remains high among men who have sex with men (MSM) living with human immunodeficiency virus (HIV) (PWH). This study determined the prevalence of asymptomatic STIs in MSM PWH attending an HIV clinic in Mexico City. METHODS: This cross-sectional study (May 2022-November 2023) included self-questionnaires on STI-related behaviors and symptoms, urethral samples for multiplex polymerase chain reaction (PCR), and serological tests for syphilis, HBV, and HCV. RESULTS: Among 261 patients, 56.7% were receiving antiretroviral therapy, 41.8% had suppressed HIV-1 viral load, and 26.1% tested positive for at least one STI in urethral PCR. The most prevalent microorganisms were CONCLUSIONS: This study underscores the high frequency of asymptomatic STIs and the importance of regular screening.