Two studies examined whether dissociation from 9/11-related thoughts and emotions would be higher after mortality salience (MS) relative to a control condition. Because dissociation is believed to contribute to anxiety disorders, we also examined whether higher ratings of dissociation after MS would lead to higher reported anxiety sensitivity. In Study 1, MS participants reported higher levels of peritraumatic dissociation from 9/11 and higher levels of anxiety sensitivity than control participants who contemplated an upcoming exam. Furthermore, the extent to which MS induced higher levels of anxiety sensitivity was fully mediated by the extent to which MS caused greater dissociation. In Study 2, we examined whether heightened anxiety sensitivity is specifically a consequence of MS-induced dissociation or whether MS-induced worldview bolstering also causes higher anxiety sensitivity. Results indicated that MS participants reported more peritraumatic dissociation from 9/11 or bolstered support for their worldview; but, whereas higher dissociation in response to a death reminder led to higher anxiety sensitivity, worldview bolstering did not. Implications for understanding the role of mortality concerns in psychological reactions to 9/11 and other acts of terrorism are briefly discussed.