High social anxiety is associated with negative interpretations of social feedback, maladaptive attributions for success and failure, and excessive attention to internal and external threat cues. In the present study, 40 undergraduate participants with either high or low levels of social anxiety engaged in a series of social interactions with varying types of social feedback: negative, mixed-negative, mixed-positive, and positive. Given the increasing engagement in computer-mediated communication among individuals with high levels of social anxiety, these interactions took place via instant messaging software. Compared to participants with low social anxiety, participants with high social anxiety experienced more self-focused thoughts, negative thoughts, and state anxiety in response to increases in negative feedback. Participants with low social anxiety experienced fewer self-focused thoughts in response to increased negative feedback, resulting in a significant crossover interaction. Qualitative and quantitative differences regarding cognitive processes and computer-mediated communication among individuals with high and low social anxiety are discussed.