Aims While randomized evidence appears to have established efficacy of cognitivebehavioral therapy (CBT) and some pharmacotherapy for social anxiety disorder (SAD), their real-world effectiveness has been called into question by long-term naturalistic cohort studies of patients with SAD as they show very low probability of recovery and sustained social dysfunctions despite some drug and psychological therapies. Method The present study examines the effectiveness of group CBT for SAD in real-world settings (n=62) by examining the course of patients' symptomatology and social functions through approximately 6 months on the waiting list, through 6 months receiving the manualized group CBT intervention consisting of 16 2-h sessions, and for 12 months after the treatment. Results We found: (i) that the patients with SAD changed little or possibly worsened through the 6 months on the waiting list, although two in three of them were on antidepressants, benzodiazepines or both; (ii) that both their symptomatology and social function improved significantly and substantively through the group CBT; and (iii) that this improvement was maintained through the 3- and 12-month follow ups. Conclusions We can implement and must disseminate evidence-based, effective CBT for more patients with SAD to lessen their suffering and stop the perpetuation of their symptoms.