Purpose: This study was conducted to ascertain the effectiveness of forest healing therapy by analyzing researches on forest healing therapy applied to Korean adults and to confirm that forest healing therapy can be used as a therapeutic intervention program for elderly nursing or rehabilitation nursing. Methods: We searched 972 research papers on forest therapy applied to Korean adults. We reviewed appropriate 25 research papers with experimental design among them in the final analysis. Results: Forest healing therapy had physiological and psychosocial effects. First of all, it showed physiological effects to reduce stress index such as heart rate variation. Forest therapy also improved melatonin level in blood of middle-aged women with menopause and increased alpha wave in electroencephalogram and decreased lipid level and superoxide dismutase in blood. Second, forest healing therapy showed psychosocial effects to reduce depression and to improve mental health. But the effects appeared differently depending on the implementing type, period of forest healing therapy, and the professionalism of therapists. Therefore, if forest healing therapy would be applied to nursing, it should be based on its key principle, in other words, its principle of action-interaction-response of forest healing therapy. Conclusion: The results of this study could be used to develop a forest healing program as an intervention of nursing.