This review aims to contribute to the ongoing discussion about human health, global change, and biodiversity by concentrating on the relationships between forests and human health. This review gives a short overview of the most important health benefits that forests provide to humans, and the risks that forests may pose to human health. Furthermore, it discusses the future challenges for the research on the links between forests and human health, and for delivering health through forests in practice. Forests provide enormous possibilities to improve human health conditions. The results of a vast amount of research show that forest visits promote both physical and mental health by reducing stress. Forests represent rich natural pharmacies by virtue of being enormous sources of plant and microbial material with known or potential medicinal or nutritional value. Forest food offers a safety net for the most vulnerable population groups in developing countries, and healthy forest ecosystems may also help in regulation of infectious diseases. Utilizing forests effectively in health promotion could reduce public health care budgets and create new sources of income. Main challenges to delivering health through forests are due to ecosystem and biodiversity degradation, deforestation, and climate change. In addition, major implementation of research results into practice is still lacking. Inadequate implementation is partly caused by insufficient evidence base and partly due to the lack of policy-makers' and practitioners' awareness of the potential of forests for improving human health. This calls for strong cooperation among researchers, policy-makers, and practitioners as well as between different sectors, especially between health and environmental professionals.