Research has identified 2 emotion-based dispositions to rash action, referred to as positive urgency and negative urgency. They are thought to reflect tendencies to engage in rash acts when in extremely positive and extremely negative moods, respectively. In this article, we describe the first direct test of this hypothesis. We measured the urgency traits and risky behavior involvement while in extremely positive and negative moods over the course of the first year of college for 292 students. After controlling for sex, typical mood state, and prior mood-based rash behavior, positive urgency predicted increases in positive mood-based rash action, and negative urgency predicted increases in negative mood-based rash action during the first year of college. These results provide further evidence for the validity of the theory of emotion-based rash action and for the measures of positive and negative urgency.