To investigate the effect of a threat to gender identity on the use of defense mechanisms, college students were given false feedback regarding their sex-role identity. Male and female students who were given gender-contrary feedback showed a marked increase in the use of the defense of identification, as compared to students who were given gender-consistent feedback. Further, both affect change and the use of identification was a function of the degree of discrepancy between feedback condition and conscious gender identity. It is the purpose of this study to investigate how a threat to gender identity influences the use of defense mechanisms. To provide the necessary context for this investigation, I first provide a brief discussion of the concept of defense mechanism and its relation to gender identity, and present what is known about the effect of threat to the self and the use of defense mechanisms.