Cognitive models propose that both, negative interpretations of ambiguous social situations and ruminative thoughts about social events contribute to the maintenance of social anxiety disorder. It has further been postulated that ruminative thoughts fuel biased negative interpretations, however, evidence is rare. The present study used a multi-method approach to assess ruminative processing following a social interaction and negative interpretation bias in a student sample screened for high and low social anxiety. Results support the hypothesis that group differences in negative interpretations (...) of ambiguous social situations in HSAs vs. LSAs are mediated by higher levels of post-event processing assessed in the questionnaire. Exploratory analyses highlight the potential role of comorbid depressive symptoms. The current findings help to advance the understanding of the association between two cognitive processes involved in social anxiety and stress the importance of ruminative post-event processing. (shrink)