The role of forests in enhancing human health and well-being has been studied in Finland for more than a decade, and these benefits are increasingly recognized by the Finnish society. The national research has studied the associations of use and availability of nature with health using different research methods such as population surveys, on-site field experiments, and combining GIS-based data describing the provision of nature areas with use of the areas and health status of people. This article sums up research results from multidisciplinary research work in Finland. One of the main study areas has been restorative effects of nature areas using various psychological measures. These studies demonstrate that forests and other nature areas are important in reducing stress and add recovery from work. Moreover, field experiments have confirmed that visiting forests have beneficial psychological and physiological effects on human health. These effects can be explained by psychological stress relief with contribution from reduced air pollution and noise exposure during the visits. In addition, studies looking at long-term effects of nature exposure suggest that physical activity has a mediating role in perceived health benefits, particularly among suburban residents. Recent efforts include national policy-science discussions on how the research knowledge can be implemented within various sectors such as public health and land-use planning and forest management. This work has resulted a suggestion for a national program called Nature for Health and Well-Being in Finland consisting of an action plan and a multidisciplinary research program. More comprehensive research knowledge has contributed to and triggered series of practical experiments and pilots that are briefly discussed in the article.