BackgroundIn Pakistan, sexual practices outside marriage are proscribed by law. We aimed to assess the range and magnitude of non-marital sexual behaviours of urban men, focusing on men having sex with men.MethodsIn this cross sectional survey undertaken in six cities of Pakistan, we interviewed 2400 men aged 16–45 years selected through a multistage systematic sampling design. Sexual behaviours were assessed through a structured questionnaire. Multivariable analysis was used to identify association between various individual level characteristics and probability of engaging in sexual activities involving men.ResultsNearly one-third (29 percent) reported having had non-marital sex in their lifetime. Of these men 16 percent reported premarital sex, while 11 percent reported engaging in both pre- and extramarital sex. Only two percent reported exclusive extramarital sex. In total 211 respondents, 9 percent reported ever having had sexual relations with men. While 62 respondents, 2.6 percent reported exclusive sex with males. Factors that were significantly associated with MSM behaviours were being less than 27 years (adjusted OR 5.4, 95% CI 3.8–7.7, p < 0.000), less than 10 years of schooling (adjusted OR 2.1, 95% CI 1.4–3.2, p < 0.000), being unemployed (adjusted OR 2.7, 95% CI 1.6–4.3, p < 0.000), being exposed to pornographic materials (adjusted OR 4.8, 95% CI 3.0–7.7, p < 0.000) and being a migrant (adjusted OR 2.1, 95% CI 1.3–3.4, p < 0.002). Factors significantly associated with exclusive homosexual behaviour were having sexual debut at a younger age i.e. 16–22 years (adjusted OR 12.5, 95% CI: 3.8–40.7, p < 0.000), being unemployed (adjusted OR 8.8, 95% CI: 3.0–26.0, p = 0.000), having had exposure to pornographic materials (adjusted OR 3.3, 95% CI: 1.5–7.2, p = 0.002).ConclusionsTo prevent the spread of STI’s in Pakistan, preventive interventions should focus on reaching out to young uneducated men offering them with appropriate counselling and skills to adopt “safe sex practices” through workplace orientation sessions; while for youth in schools, life skills education be included in the curriculum. Through public-private partnership stigmatised groups should be reached through established community networks and provided with information on accessing voluntary counseling and treatment centres.