A cross-sectional analysis was conducted to describe unsafe sexual practices among HIV-infected men under care in two Brazilian urban areas. Data were collected by face-to-face interviews. Twenty-five percent practiced unprotected sex in the previous year, 16% were abstinent, 33% had sex with men only, 45% with women only, 48% had male/female stable partners, 84% were on HAART and 48% had AIDS. Illicit drug use, number of female partners, having stable partners, and STD diagnosis were associated with unsafe sex. Interventions to reduce risk taking behavior among HIV-positive men under care in these settings are urgent, especially among heterosexual stable couples.