We present a self-enhancement model of workplace incivility to account for the effects of exposure to incivility on task performance. In particular, we predict that workplace incivility thwarts one's ability to self-enhance at work, resulting in employees divesting their sense of self from work via disengagement processes. Maintaining high levels of task performance subsequently ceases to be a source of self-enhancement for employees who have disengaged their sense of self from work. We also examined the extent to which the desire for self-enhancement (i.e., narcissism) moderated the effect of incivility on engagement. Using two multi-wave, multi-source data collected in China, our results provide full support for our hypotheses, address untested theoretical predictions and provide new theoretical directions for incivility research.