BACKGROUND: Coping with Depression Course (CWD) has shown to be effective in the treatment of depression. However, there are very few randomized controlled trials on unipolar depression in adults. AIMS: To test the effect of a modified CWD on unipolar depression in a randomized controlled trial design in adults. METHODS: Participants were recruited through mass media, tested by BDI and clinical interview, and randomized into intervention group (N = 81) and control group (N = 74). The program was mainly conducted by nurses with background in psychiatry and primary health care, and the intervention encompassed 8 weekly sessions of 2 1/2 hours, with 3 booster sessions. RESULTS: By "intention-to-treat" analysis a statistically significant effect on depressive symptoms at follow up at 6 months was found, and the level of symptoms was sustained after 12 months. CONCLUSION: The study shows that the intervention is effective in the treatment of unipolar depression, and suitable for specialized psychiatric services as well as primary health care.