Erectile dysfunction (ED) has been associated with considerable mental health and interpersonal problems, an increase in risky sex, and is particularly prevalent among gay and bisexual men. Psychological treatment protocols for sexual dysfunctions often aim at challenging beliefs and cognitions about the importance of a “perfect sexual performance,” known as sexual stereotypes. However, to date, little empirical evidence exists for the relationship between ED and belief in sexual stereotypes (BSS). To address this gap, 70 gay men were recruited; 30 with ED and 40 healthy controls. Participants completed a battery of questionnaires, including a measure of BSS, followed by having their genital temperature measured using a thermal imaging camera, while viewing a sexually explicit film. The study had four main objectives: (1) to evaluate between group differences in subjective sexual arousal and physiological arousal; (2) to examine within group differences in the effects of BSS on physiological and self-reported sexual arousal; (3) to evaluate the relationship between BSS, negative automatic thoughts during sex, and ED; and (4) to evaluate the relationship between ED and risky sex among gay men. Results revealed significant between-group differences in physiological arousal, but not in subjective sexual arousal. While between-group differences were found in BSS, no within-group differences were found in the relation of BSS on physiological and self-reported sexual arousal. No significant relationships were found between BSS, negative automatic thoughts, and ED. Participants with ED were found to be significantly more likely to use erectile enhancing drugs, but no significant differences in condom removal were found between groups; however, substantially more individuals with ED (23.3%) reported removing condoms prior to the completion of sexual activity, as compared to healthy controls (5%). Findings of this study contribute to improving psychological treatments for gay men with ED, as well as better understanding pathways leading to risky sex in gay men.