This study compared the effects of cognitive defusion and thought distraction on fear of negative evaluation, dysfunctional attitude, and negative emotions (specifically, anxiety and depression). Eighty-one Korean college students with social anxiety participated in this study. They were randomly assigned to one of three conditions: Cognitive Defusion (CD), Thought Distraction (TD), or Control. Using pre-test scores as the covariate, Analysis of Covariance (ANCOVA) and Multivariate Analysis of Covariance (MANCOVA) compared post-test scores of the three conditions. After the intervention of each condition, the participants assigned to the CD condition showed significantly lower levels of fear of negative evaluation and dysfunctional attitude than the TD condition. The CD and TD interventions did not show significant differences in anxiety and depression levels; however, both interventions turned out to be significantly effective compared to the Control condition. These findings suggest that cognitive defusion may be a more effective strategy than thought distraction for relieving the cognitive aspects of social anxiety.