Psychological treatments for social anxiety disorder (SAD) in adolescents have shown poorer outcomes than for other anxiety disorders. A relevant factor to consider for improving outcomes may be negative imagery. In this pilot study, we examined negative ‘flashforward’ imagery of feared catastrophic outcomes in adolescents with SAD and evaluated the feasibility and preliminary outcomes of a short eye movement desensitization and reprocessing (EMDR) intervention targeting this imagery. We used a case series design with a 1‐week baseline period. Outcomes included symptoms of social anxiety and avoidance related to selected social situations and features of associated flashforward imagery as the proposed mechanism of change during the intervention. We found that six out of seven assessed adolescents reported to experience flashforwards and rated image distress, vividness and threat appraisal as high. In these six participants (aged 14–17 years old), the short EMDR flashforward intervention appeared feasible and was followed by a decrease in social anxiety and avoidance in five participants, while no notable changes were observed during the baseline period. Furthermore, we observed a decrease in flashforward imagery features in at least five participants. Nonparametric tests of the overall (group‐based) changes during the intervention period partially supported these findings. Limitations include the small sample size and the lack of a control group. Results suggest that vivid and distressing flashforward imagery is a common experience and that targeting flashforwards with EMDR may be beneficial in treating social anxiety in youth. Further experimental research on effects and added value to current treatments is necessary.Trial Registration: Dutch Clinical Trial Register (National Trial Register [NTR]): NL8974