Much research has examined the impact of HIV-associated stigma on HIV-positive individuals, but little work has explored its impact on HIV-negative persons. However, many gay and bisexual men may imagine the stigma they would experience upon seroconverting, and this anticipated stigma may be associated with negative mental health. Such concerns may be exacerbated among men who identify with the receptive role during anal sex, because of greater risk for infection. This study examined the association between anticipated HIV stigma and negative affect among 683 HIV-negative gay and bisexual men living in New York City. Anticipated HIV stigma predicted negative affect over and above internalized homonegativity. Sexual role identity was associated directly with anticipated stigma and indirectly with negative affect. Results suggest that anticipated HIV stigma may be an important mental health issue for gay and bisexual men. Public health messaging discussing sexual positioning should be sensitive to the potential for exacerbating anticipated HIV stigma among bottom-identified men.