We report four independent studies that examined the relationship between social interaction anxiety and the tendency to interpret positive social events in a threat-maintaining manner. Study 1 described the development of a scale that measures negative interpretations of positive social events, the interpretation of positive events scale (IPES). Study 2 cross-validated the structure of the IPES and established that social interaction anxiety explained significant variance in negative interpretations of positive social events beyond negative affect in general. Study 3 demonstrated that negative interpretation of positive events was significantly greater in a clinical sample of patients with generalized social anxiety disorder (GSAD) than a matched group of non-anxious community controls. In addition, within the GSAD group, the IPES was associated with negative social predictions following a positive interaction. Finally, study 4 confirmed that negative interpretations of positive social events mediated the relationship between social interaction anxiety and low positive affect.