Self-discrepancy theory posits that people experience emotional consequences when they perceive discrepancies between their actual and possible selves. However, the extent to which people react emotionally to these self-discrepancies (i.e. ideal, ought and undesired) may be a function of individual differences in neuroticism. Across both experimental (Study 1; N = 155) and correlational designs (Study 2; N = 139) involving college students, the authors demonstrated that neuroticism moderated the discrepancy–emotion associations such that high-neuroticism individuals showed elevated depression and anxiety symptoms when their self-discrepancies were activated. The heightened symptoms were maintained over time. Negative repetitive thoughts (i.e. rumination and worry) were examined as potential mediating mechanisms between the discrepancy × neuroticism interaction and symptoms. Partial support was obtained in that rumination mediated between undesired discrepancy × neuroticism interaction and anxious/depressive symptoms. Implications and possible theoretical extensions for self-discrepancy theory are discussed. Copyright © 2012 John Wiley & Sons, Ltd.