Four experiments were conducted to study the effect of self-focused attention on affective reactions. In addition, the research was also intended to help resolve the controversy over attentional versus arousal explanations of self-awareness research. In Experiment 1, undergraduate men were asked to view and rate slides of nude women in the presence of a mirror or with no mirror. In Experiment 3, subjects were either exposed or not exposed to a mirror and read a set of mood statements which became either increasingly positive or increasingly negative. Experiments 2 and 4 conceptually replicated Experiments 1 and 3 by selecting subjects on the basis of private self-consciousness. In each study, self-focused attention increased the person's responsiveness to his transient affective state. The convergence between mirror-manipulated self-awareness and private self-consciousness was offered as support for an attentional interpretation of the findings. The implications of the research for self-awareness theory are discussed.