This experimental study examined the moderating role of masculinity contingent self-worth (CSW) in the effects of masculinity threat on transprejudice. One hundred and eighty-six male undergraduate students were randomly assigned to one of the three conditions. In the first condition, participants received feedback that challenged their sense of manhood (masculinity threat group). In the second condition, participants received feedback that affirmed their masculinity (masculinity affirming group), whereas the third group of participants served as a control group. The masculinity threat group demonstrated stronger transprejudice than the other two groups, whereas no differences were found between the affirming and control groups. The effect of masculinity threat on transprejudice was particularly strong for participants whose self-worth is readily threatened by a lack of masculinity (i.e., the threat aspect of masculinity CSW). However, individual differences in the boost aspect of masculinity CSW (i.e. the extent to which a person’s self-worth is boosted by confirmations of masculinity) did not moderate the influence of masculinity threat on transprejudice. This study replicates previous evidence that masculinity threat is a cause of transprejudice, whereas it highlights the distinction between the threat and boost dimensions of masculinity CSW by showing that the effects of masculinity threat were only moderated by the threat dimension.