This chapter focuses on the research and practice of forest therapy. Forest therapy has been developed and studied intensively in Korea from the perspective of the authors, experienced and leading researchers on the topic of forest therapy and as a former minister of the Korean Forest Service. As for studies in the field of forest therapy, they have been conducted across these diverse fields and are beginning to shape a clear picture of the psychological, physiological, and physical effects of forests and natural environments on human beings. Physiological changes are indicators of important health-related effects of forest use. Although forest therapy programs vary in the target populations and practices, most studies report the effects of forest therapy programs positively indicating that forest therapy programs practically have significant potential in the areas personal growth including self-concept and the promotion of positive human relations.