Five studies investigated the hypotheses that the sense of power increases optimism in perceiving risks and leads to more risky behavior. In Studies 1 and 2, individuals with a higher generalized sense of power and those primed with a high-power mind-set were more optimistic in their perceptions of risk. Study 3 primed the concept of power nonconsciously and found that both power and gain/loss frame had independent effects on risk preferences. In Study 4, those primed with a high-power mind-set were more likely to act in a risk-seeking fashion (i.e., engage in unprotected sex). In Study 5, individuals with a higher sense of power in a face-to-face negotiation took more risks by divulging their interests. The effects of power on risk-taking were mediated by optimistic risk perceptions and not by self-efficacy beliefs. Further, these effects were attenuated when the high-power individual felt a sense of responsibility. Copyright © 2006 John Wiley & Sons, Ltd.