Does narcissism provide a source of hardiness or vulnerability in the face of adversity? The present research addressed this question by testing whether narcissism is associated with increased physiological reactivity to emotional distress, among women. Drawing on the "fragile-ego" account, we predicted that narcissists would show a heightened physiological stress profile in response to everyday frustrations. Results supported this prediction; across a 3-day period, highly narcissistic individuals showed elevated output of 2 biomarkers of stress--cortisol and alpha--amylase-to the extent that they experienced negative emotions. In contrast, among those low in narcissism there was no association between these biomarkers and emotions. These findings suggest that narcissists' stress-response systems are particularly sensitive to everyday negative emotions, consistent with the notion that narcissism comes with physiological costs.