Although it is well-established that vulnerability to negative emotion is associated with attentional bias toward aversive information, the causal basis of this association remains undetermined. Two studies addressed this issue by experimentally inducing differential attentional responses to emotional stimuli using a modified dot probe task, and then examining the impact of such attentional manipulation on subsequent emotional vulnerability. The results supported the hypothesis that the induction of attentional bias should serve to modify emotional vulnerability, as revealed by participants' emotional reactions to a final standardized stress task. These findings provide a sound empirical basis for the previously speculative proposal that attentional bias can causally mediate emotional vulnerability, and they suggest the possibility that cognitive-experimental procedures designed to modify selective information processing may have potential therapeutic value.