Objective: Recent theories emphasize the contribution of emotion regulation (ER) difficulties to psychopathology. The present study sought to identify patterns of ER difficulties in social anxiety disorder (SAD) and to test the predictive value of these difficulties for actual anxious responding during the anticipation of a social evaluative task. Method: Participants diagnosed with SAD (n = 67) and healthy controls (n = 59) completed self-ratings of ER difficulties (DERS) and depressive symptoms. This was followed by the announcement of an impromptu speech. During the anticipation period, subjective ratings of anxiety and arousal were assessed. Results: Compared to healthy controls, SAD participants reported significantly higher levels of ER difficulties. With the exception of "lack of emotional awareness," these differences remained significant when controlling for depression. ER difficulties also contributed to anxious responding during the stress test; but this held true only for nonclinical participants. Conclusion: SAD is characterized by a wide range of ER deficits. However, the associations between ER difficulties and symptoms of anxiety remain poorly understood.