The aims of this study were twofold: to examine the empirical evidence supporting the positive contribution that a forest environment can make on human psychological health and well-being and to describe the theoretical framework within which the forest environment has this effect. Our review of the literature provides empirical evidence that a forest experience can contribute to improved emotional and cognitive health.This experience can be through a forest activity program and by experiencing the social and physical conditions of the forest environment and the therapeutic elements of the forest. Visiting or viewing a forest scene has been documented to have a positive effect on psychological healing and well-being in terms of recovering from stress, improving concentration and productivity, improving the psychological state, particularly for people from urban environments. Wilderness and related studies clearly demonstrate that being in a forest environment has a positive effect on people, while results from other studies indicate that contacts with forest environments provide multiple positive physiological and psychological effects on human health that included decreasing the blood pressure and heart rate and reducing anxiety and stress. There are several theories explaining the healing effects of the forest on human beings. Most hypothesize that restorative environments are settings in which recovery is associated with the reduction of stress and that the benefits of contact with natures include a wide range of positive physiological and psychological responses. These theories are based on an evolutionary perspective and share a number of similarities and differences. This article summarizes a number of these theories of restorative environments as well as addresses the current status of forest therapy and the challenges and opportunities for therapeutic effects of the forest in Korea.