Researchers have theorized that changing the way we think about our bodily responses can improve our physiological and cognitive reactions to stressful events. However, the underlying processes through which mental states improve downstream outcomes are not well understood. To this end, we examined whether reappraising stress-induced arousal could improve cardiovascular outcomes and decrease attentional bias for emotionally negative information. Participants were randomly assigned to either a reappraisal condition in which they were instructed to think about their physiological arousal during a stressful task as functional and adaptive, or to 1 of 2 control conditions: attention reorientation and no instructions. Relative to controls, participants instructed to reappraise their arousal exhibited more adaptive cardiovascular stress responses--increased cardiac efficiency and lower vascular resistance--and decreased attentional bias. Thus, reappraising arousal shows physiological and cognitive benefits. Implications for health and potential clinical applications are discussed. (Contains 2 figures and 2 footnotes.)