Our objective was to identify sexual behaviours related to risk of HIV infection. A cluster survey of sexually experienced men from diverse sociodemographic settings in Bogotá, Colombia was carried out using a standardized self-administered questionnaire. A high response rate (96%) resulted in the enrollment of 553 men. Most participants 129/442 reported having intercourse with women and 51/111 reported having sex with other men. Most respondents (90%) engaged in high-risk sexual practices; only 2% knew their HIV-1 serostatus. Consistent condom use was reported by 20% of those who practised anal sex, and was even lower (5%) among men who had sex with women during menses. Heterosexuals exhibited a higher degree of risky sexual patterns than homosexual/bisexuals (P=0.01). In conclusion, high-risk sexual practices are prevalent among men in Bogotá, particularly heterosexuals, attesting to the urgent need for effective and specific interventions to prevent HIV transmission.