<p class="abstract"><strong>Background:</strong> In India the estimated men who have sex with men (MSM) population is around 352, 000, among that 4.3% are living with HIV. The incidence of sexually transmitted infections (STIs) in MSM is greater than that reported in women and men who have sex with women only. The aim of the study is to determine the trends of sexual behaviour and the pattern of sexually transmitted infections in men who have sex with men.</p><p class="abstract"><strong>Methods:</strong> A retrospective study of the data collected from the clinical records of all MSM, who had attended the STI clinic of Kilpauk Medical College, Chennai, Tamil Nadu, during the three-year study period, from July 2016 to June 2019. Demographic data, sexual risk behaviour, condom usage and STIs, among the MSM, were computed and analyzed.<strong></strong></p><p class="abstract"><strong>Results:</strong> During the study period 489 MSM attended the STI clinic, 51.9% were bisexual and 48.1 % were homosexual. Among them, exclusive penetrative sex in 50.7%, exclusive receptive sex in 15.7% and both in 33.6% were reported. Condom usage was consistent in 18.8%, inconsistent in 28.8% and 52.9% never used condom. Unprotected sex is more common in oral sex than with anal sex. STIs were seen in 20.9% and HIV in 1.4% of MSM. Syphilis was the most common STI seen.</p><p class="abstract"><strong>Conclusions:</strong> Our study elucidated the high prevalence of STIs among MSM and increasing trends of sexual risk behaviour. Health service providers must take necessary steps to improve the provision of biological and medical measures to screen, treat and prevent infections.</p><p class="abstract"> </p>