Group psychotherapy for social anxiety disorder (SAD) is an established treatment supported by findings from primary studies and earlier meta-analyses. However, a comprehensive summary of the recent evidence is still pending. This meta-analysis investigates the efficacy of group psychotherapy for adult patients with SAD. A literature search identified 36 randomized-controlled trials examining 2171 patients. Available studies used mainly cognitive-behavioral group therapies (CBGT); therefore, quantitative analyses were done for CBGT. Medium to large positive effects emerged for wait list-controlled trials for specific symptomatology: g = 0.84, 95% CI [0.72; 0.97] and general psychopathology: g = 0.62, 95% CI [0.36; 0.89]. Group psychotherapy was also superior to common factor control conditions in alleviating symptoms of SAD, but not in improving general psychopathology. No differences appeared for direct comparisons of group psychotherapy and individual psychotherapy or pharmacotherapy. Hence, group psychotherapy for SAD is an efficacious treatment, equivalent to other treatment formats.