This study investigated whether positive feedback from same-age peers can modify self-relevant cognitive processes of high socially anxious youth in a positive direction. Thirty-three high socially anxious and 32 non-socially anxious undergraduate students (17–22 years) gave an impromptu speech and received either positive or neutral feedback post-speech. Anticipatory processing (AP) was rated prior to the speech via self-report. One week later participants returned to the laboratory and completed questionnaires assessing post-event processing (PEP) thoughts related to the impromptu speech and AP about a future speech. For high socially anxious youth receiving positive feedback, AP about their speech performance significantly improved over time. In addition, high socially anxious participants who received positive feedback reported a higher frequency of positive PEP thoughts about their speech in the intervening week. These improvements did not occur in the neutral peer feedback condition. Non-socially anxious participants’ AP improved in both feedback conditions, whereas their frequency of PEP was unaffected by feedback. These findings suggest that, in high socially anxious youth, positive feedback from same-age peers can modify self-relevant cognitive processes in a positive direction. We discuss how methodological improvements could more thoroughly investigate the potential of positive peer feedback for changing cognitions.