Heterosexual contact with drug users is a major route of AIDS transmission. This study of 135 male and 109 female methadone maintenance patients described subjects' sexual behavior, preventive practices and attitudes toward safer sex; explored ethnic-racial differences in high risk sexual behavior and attitudes; and examined the relationship between attitudes toward safer sex and frequency of condom use for men and women. Reported condom use was low, and it correlated with attitudes toward safer sex. Men tended to report higher rates of sexual risk-taking, although women reported more frequent sex with IV drug users. Study findings have implications for developing intervention strategies to reduce risk behavior associated with HIV transmission.