BACKGROUND Men having sex with men are recognised as high-risk group in view of STI/HIV (sexually transmitted infection/human deficiency virus) transmission. In India, HIV estimations of the year 2015, reaffirm the country’s success story in responding to HIV/AIDS (acquired immunodeficiency syndrome) epidemic. India has successfully achieved the 6th Millennium Development Goal of Halting and Reversing the HIV epidemic. As per National AIDS Control Organization Technical Report at national level, the adult HIV prevalence has continued to show a steady decline, the same scenario in MSM also. Reduction of HIV new infections is testimony of impact of prevention programs. The aim of the study is to know the social factors influencing behavioural pattern and prevalence of HIV/STI among MSM attending STI clinic in a tertiary care hospital. MATERIALS AND METHODS A prospective study was conducted in a STI Clinic attached to a tertiary care hospital of South India. MSM attending the STI Clinic between October 2015-December 2016, who have consented were included in this study. This includes direct walk-in MSM clients who disclose their behaviour on routine counseling done at STI Clinic and line listed MSMs brought by TI NGO (targeted intervention, non-governmental organization). After getting consent, a detailed history taking clinical examination and serological tests for HIV and STI were done. RESULTS Most of the participants are unmarried (72%) with school level education (65.5%), half of the participants are skilled workers and professionals. Practicing unsafe sex remains the same among educated and uneducated persons of study group, only 34% of participants practice safe sex. 21.8% of participants presented with clinical manifestations of significance. Among STI, syphilis was common. CONCLUSION MSM are important in the context of STI/HIV prevention. Prevalence of STI and inconsistent condom use among MSM of this study group indicates the need of strengthening of prevention programs. Information and motivation for risk reduction cannot be an one time effort for prevention. Continuous interventionary models will help them for risk reduction. The percentage of partner screening was less in this study. The stigma associated with MSM behaviour and STI maybe a reason. MSMs use social media to meet their clients. Newer preventive programs via social media in the area of STI/HIV prevention maybe of help in future.