This study investigated the joint influence of trait social anxiety and evaluative threat on psychological and cardiovascular responses to active coping situations. Fifty-two normotensive female students characterized as either high or low in trait social anxiety performed a mental arithmetic task and a speech task requiring persuasive behavior in a context of high or low evaluative threat. Trait social anxiety exerted a substantial influence on cardiovascular reactivity. High socially anxious individuals overall exhibited greater heart rate reactivity. For systolic and diastolic blood pressure enhanced reactivity of socially anxious individuals was confined to low evaluative threat. At high levels of evaluative threat no group differences were observed due to somewhat attenuated reactivity in high compared to low socially anxious individuals. Cognitive appraisals and affective arousal were not found to mediate the effects of social anxiety on cardiovascular reactivity. Results were attributed to differences in effort expenditure rather than experienced anxiety.