Objectives: The present study was designed to verify efficacy of cognitive-behavioral group therapy (CBGT) in reducing irrational belief and depression symptoms among female outpatients with depressive disorder and to help develop a program of CBGT that can be applied in clinics. Methods: Twenty-nine female patients meeting the DSM-IV criteria for dysthymic disorder were assigned to either 10 weekly CBGT sessions (treatment group, n=14) or a waiting list (control group, n=15). The group leader was a psychiatrist. Based on the Stanford cognitive group therapeutic program, an appropriate program was developed that could be applied in a clinic. The two groups were followed for two months and the following outcome measures were applied: Beck's depression inventory, the Chinese version of the cognitive style test and the cognitive error questionnaire. These measures were used on three occasions, two weeks before the study, immediately upon completion of therapy and two months after completion of therapy. All the participants who completed the program underwent the pretest, posttest and follow-up assessments. Results: Twenty-three female patients completed the research program (treatment group, n=11; control group, n=12). The results suggest that CBGT is effective in reducing the intensity of depression symptoms and irrational beliefs. The results also show that the levels of psychopathological symptoms remain relatively stable over the two months follow-up after treatment. Conclusion: These findings can be taken as further evidence supporting the efficacy of CBGT in the treatment of depressive disorder.