Despite anecdotal reports suggesting that bupropion may be effective for panic disorder, both clinical lore and the results of one small controlled study suggest otherwise. There remains a paucity of systematic prospective data addressing this issue. Twenty outpatients meeting criteria for panic disorder with or without agoraphobia were entered in an 8 week, two center open-label flexible dose trial of bupropion SR. Treatment with bupropion SR resulted in a clinically and statistically significant mean reduction of 1 to 2 points in the primary outcome measure, the CGI Severity score, in both the intent to treat (ITT; t=4.36, df=19, p<0.001) and completer samples (t=3.89, df=13, p<0.002). Significant improvement was also noted in both completer and ITT samples for all other panic symptom measures, which included the Panic Disorder Severity Scale (PDSS), number of panic attacks in the past two weeks, and the proportion of time anticipatory anxiety was present. Although results may be influenced by the open nature of this trial, our findings suggest that bupropion SR may be effective for the treatment of panic disorder. Further controlled study of its efficacy for this condition are warranted.