Cognitive fusion (CF) and experiential avoidance (EA) are two constructs of acceptance and commitment therapy that contribute to psychological distress. The current study aimed to examine whether CF and EA accounted for variance in the relationships between key cognitive maintaining factors of social anxiety and indicators of social anxiety. This issue was investigated using a longitudinal design in a nonclinical sample. Participants ( N = 361) completed baseline measures of CF, EA, cognitive maintaining factors, and indicators of social anxiety, and the measures of indicators of social anxiety were recompleted 6 weeks later ( N = 262). Results showed that baseline postevent processing had significant indirect effects on fear of negative evaluation at follow-up: (a) via CF, (b) via EA, and (c) via a serial pathway of CF → EA. Interventions that aim to reduce CF, in particular, may be a priority in reducing fear of negative evaluation associated with postevent processing.