BackgroundMycoplasma genitalium (MG) is an emerging sexually transmitted infection (STI) for whose management remains controversial. We aimed to assess the prevalence and risk factors of MG infection in patients attending an STI clinic in Reunion Island.MethodsBetween January 2017 and December 2018, all patients attending the Saint-Pierre STI clinic in Reunion Island were screened for MG, Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG). Urogenital, pharyngeal and/or anal samples were collected based on sexual behaviour and analysed by triplex PCR. Risk factors were identified using a Poisson regression for binary outcome.ResultsAmong 2069 screened subjects, the overall prevalence of MG was 4.88% [95% Confidence Interval (CI) 3.98–5.93]. The prevalence of urogenital MG was 4.38%, with women being more affected than men (5.33% vs 3.22%, prevalence ratio (PR) 1.66, p = 0.02). The prevalence of anal MG was 3.06% and that of pharyngeal MG was 0.61%, with men being more affected in both cases. Infection with MG was independently associated with multiple partners (6–10 partners: adjusted prevalence ratio-aPR 2.55, p < 0.048; > 10 partners: aPR 4.33, p < 0.004), previous history of STI (aPR 1.89, p = 0.026), non-use of condoms (aPR 2.56, p < 0.003) and co-infection with CT (aPR 2.56, p < 0.017).ConclusionCompared to other countries, the prevalence of MG is high in Reunion Island, especially in women aged under 25 years, and co-infection with CT is common. Routine MG screening and treatment should be performed in at-risk women and co-infection with MG should be considered when deciding on treatment for CT, particularly in regions where azithromycin is still in use.