Despite reports of high prevalence of human immunodeficiency virus (HIV) and other sexually transmitted diseases (STDs) among the transgender community, very little prevention education has targeted this population. To fill this gap, we developed and evaluated a transgender-specific intervention, All Gender Health, which incorporates prevention strategies into comprehensive sexuality education. Transgender participants (N=181) attended the two-day seminar in community-based venues. The curriculum was delivered via lectures, panel discussions, videos, music, exercises and small group discussions. Attitudes toward condom use, safer sex self-efficacy and sexual risk behaviour were evaluated before participation in the intervention (pre-test), immediately after participation (post-test) and at three-month follow-up. Compared to pre-test values, significant improvements were seen in attitudes toward condom use and in safer sex self-efficacy at post-test, and in attitudes toward condom use, increased monogamy and decreased sexual risk behaviour at three-month follow-up. Pre-test data identified unprotected anal, vaginal and oral sex as the most commonly reported risk behaviours. Many respondents also indicated problems with social discrimination, depression, suicidal ideation and sexual functioning. Future interventions should address these risk co-factors. Alternative interventions need to be developed to target those who, as a result of social marginalization, are less likely to be reached with an intensive seminar-based intervention.