This research attempts to understand the effect of HIV stigma on sexual affect (i.e., sexual anxiety) and the role sexual affect plays in the relationship between HIV stigma and mental health. Participants were 60 HIV-positive, sexually active adults. HIV stigma was found to have a negative effect on sexual anxiety. Further, the effect of HIV stigma on mental health was mediated by sexual anxiety. In other words, HIV stigma negatively affects individuals' anxious feelings about their sexuality, and these feelings negatively impact mental health. These findings highlight the importance of understanding psychological aspects of sexuality in the affect of HIV stigma.