Data from early studies of selective serotonin reuptake inhibitors have shown that these agents are effective in the treatment of social anxiety disorder (social phobia). This review highlights the outcomes of three large clinical trials of paroxetine in patients with social anxiety disorder. In two of the studies, patients received a flexible dose of paroxetine (20-50 mg/day) or placebo; the third trial was a fixed-dose study, in which patients received paroxetine 20, 40, or 60 mg/day, or placebo. A total of 861 subjects were randomized to treatment for 12 weeks, in centers across the U.S.A., Canada, Europe, and South Africa. The primary outcome measures were the Clinical Global Impressions (CGI) Global Improvement item and Liebowitz Social Anxiety Scale (LSAS) Total Score. In each of the studies, 45-66% of patients receiving paroxetine were rated as responders (very much or much improved on the CGI scale). Paroxetine treatment improved symptoms of social anxiety, as measured by the LSAS, compared with placebo. Differences between paroxetine and placebo groups were statistically significant and were clinically relevant within each study. In general, paroxetine was well tolerated. Paroxetine is effective for the treatment of social anxiety disorder. Based on the findings from these studies, a starting dose of 20 mg/day is recommended. The range of efficacy appears to be 20-50 mg/day for most patients.