Some heterosexual men express sexual interest in feminine trans individuals with penises. It is possible that this interest arises from a tendency for heterosexual men to be sexually responsive to gender in addition to sex. We compared the self-reported sexual attraction and visual attention patterns of Canadian undergraduate heterosexual men (N = 51) and gay men (N = 20) to nude images of feminine trans individuals with penises, cisgender men, and cisgender women. Heterosexual men were most attracted to cisgender women and fixated on them the longest. However, they were more attracted to feminine trans individuals with penises than to cisgender men. They also biased their attention to feminine trans individuals with penises over cisgender men. This pattern was unique to heterosexual men. Gay men were most attracted to cisgender men and allocated the most visual attention to them. They responded to feminine trans individuals and cisgender women in a relatively similar manner. As such, heterosexual men appear to be responsive to sex and gender, which may account for sexual interest in feminine trans individuals among some heterosexual men.