In two studies, participants preselected on their extreme scores on the Narcissistic Personality Inventory were assessed for self-complexity and evaluative integration. Then, for 5 (Study 1) or 6 (Study 2) consecutive days, they recorded their moods, self-esteem, and daily experiences. Narcissists displayed greater positive mood variability, mood intensity, and self-esteem instability than did less narcissistic individuals. Narcissism self-complexity, and evaluative integration were unrelated; however, narcissists who were low in evaluative integration experienced the greatest self-esteem instability Narcissism also interacted with daily events such that relative to less narcissistic individuals, negative interpersonal events increased self-esteem instability, and positive interpersonal events decreased self-esteem instability. The findings are discussed within reference to a social-cognitive-in terpersonal model of narcissistic behavior.