Objectives: We assessed HIV-1 infection among men who have sex with men (MSM) attending Silom Community Clinic (SCC) in Bangkok, Thailand from 2005 to 2018. Since 2014, Thailand increased implementation of HIV prevention strategies including pre-exposure prophylaxis and Treatment as Prevention. Methods: MSM attending SCC were tested for HIV using rapid tests. We assessed trends in HIV prevalence, incidence and compared incidence before and after 2014. Results: From 2005 to 2018, 14,034 clients attended SCC for HIV testing. The HIV prevalence increased from 19.2% in 2005–2006 to 34–0% in 2010, remained stable until 2016 and decreased to 17.2% in 2018 (p