We propose that men scoring higher in precarious manhood beliefs (PMB) express amusement with sexist and anti-gay humor (but not other forms of humor) in response to masculinity threat in order to reaffirm their masculinity. Accordingly, Experiment 1 (166 heterosexual men in the United States recruited through Amazon.com’s Mechanical Turk) supported the hypothesis that men higher in PMB express greater amusement with sexist and anti-gay jokes after experiencing a threat to their masculinity but not in the absence of masculinity threat. Also, the significant positive relationship between PMB and amusement following a masculinity threat was unique to the sexist and anti-gay jokes; it did not emerge for anti-Muslim and neutral jokes. Experiment 2 (221 heterosexual men in the United States recruited through Amazon.com’s Mechanical Turk) extended the findings of Experiment 1, supporting the hypothesis that, following a masculinity threat, men higher in PMB express amusement with sexist and anti-gay humor because they believe it reaffirms their masculinity. Thus, our findings suggest that sexist and anti-gay humor serve a self-affirming function for men who possess higher PMB in situations that threaten one’s masculinity. By uncovering a novel psychological function of sexist and anti-gay humor in social settings, we hope the present research will lead to better understandings of the kinds of situations that foster its occurrence and ultimately to strategies for preventing it.