This study examined the association between trait anxiety and the reactivity of the defensive motivational system, as indexed by the cardiac defense response (CDR) to an unexpected, intense noise, in a mixed-gender undergraduate sample. Gender-specific effects were observed: only women showed an association between trait anxiety and the CDR, consisting of a more intense, prompter, and durable defensive response in high-anxious women. This association was not evident during the first component of the defensive response ¿ identified as an attentional process of stimulus rejection ¿ but in later components reflecting attentional orienting and motivational processes of energetic mobilization for setting an active defensive response ¿ which might suggest reduced parasympathetic dominance along with increased sympathetic dominance. These findings in an unselected sample are consistentwith the proposal of a more reactive defensive motivational system as a potential vulnerability factor towards anxiety manifestations in women.