This study compares the relative accuracy of targets’ self-reports and other-reports of personality in predicting two criteria: (a) emotional experience in daily life and (b) behavior in the laboratory. Ratings of the targets’ extraversion and neuroticism were obtained from two knowledgeable informants and the targets themselves. Target participants wore an electronic signaling device (‘beeper’) for eight days and rated positive and negative emotions at four randomly selected times each day. The participants also interacted with an opposite-sex stranger in a laboratory context and their behavior was coded from videotapes. Targets’ self-reports of personality were consistently more accurate than other-reports in predicting daily emotional experience. Self- reports also outperformed other-reports in predicting extraversion-related laboratory behaviors, but not neuroticism-related behaviors. The relative accuracy of self- and other-reports of personality would seem to depend on the criterion employed; self-reports are clearly better for the prediction of emotional experience, while for behavior the picture is mixed.