Effectiveness of Group based Cognitive Behavioral Therapy was investigated in a sample of 23 Iranian migrants living in Austria for an average 14 years and suffering from Major Depressive Disorder. The participants were randomized to: (1) individual CBT, (2) group based CBT and (3) wait-list control groups. Although the results showed a significant decrease in depression symptoms, no significant group differences were observed. The findings from this study suggest that the effectiveness of group based CBT may be influenced by Iranian socio-cultural characteristics