When faced with self-threat, people often engage in self-protective reactions. Yet not everyone does. The extent to which self-protection occurs, is thought to depend on people’s personality. We put this claim to test by considering multiple personality traits from different content domains. In an experiment, participants (N = 1744) performed a bogus performance test and received negative versus positive feedback. As an indicator of self-protective reactions, we assessed participants’ tendency to question the validity of the test. We found that high self-esteem and high narcissism predicted stronger self-protective reactions, particularly when these traits were assessed in the content domain targeted by the negative feedback. Contrary to our hypotheses, the self-insight motive and mindfulness also predicted stronger (and not weaker) self-protective reactions. These findings provide better understanding of the role that personality plays in motivated reasoning.