The self allows us to reflect on our own behavior and to imagine what others think of us. Clinical experience suggests that these abilities may be impaired in people with personality disorders. They do not recognize the impact that their behavior has on others, and they have difficulty understanding how they are seen by others. We collected information regarding pathological personality traits—using both self and peer report measures—from groups of people who knew each other well . In previous papers, we (...) have reported that agreement between self-report and peer-report is only modest. In this paper, we address the question: Do people know that others disagree with their own perceptions of themselves? We found that expected peer scores predicted variability in peer report over and above self-report for all 10 diagnostic traits. People do have some incremental knowledge of how they are viewed by others, but they do not tell you about it unless you ask them to do so; the knowledge is not reflected in ordinary self-report data. Among participants who expect their peers to describe them as narcissistic, those who agree with this assessment are viewed as being less narcissistic by their peers than those who deny being narcissistic. It therefore appears that insight into how one is viewed by others can moderate negative impressions fostered by PD traits. (shrink)