Climate change and modern environmental problems are mostly caused by the way economic growth of developed countries. Urbanization has reduced green areas. Sustainable development has grown from a current problem into an imperative for the development of modern civilization. Since values, attitudes, and patterns of behavior are adopted at the earliest age, this is precisely the moment when education for sustainable development needs to begin. The forest is an exceptional and healthy learning location that provides sensory experiences, much more than other ecosystems, encourages the ability to observe and listen, stimulates social interactions among children, and forest kindergartens are an ideal place for experiential learning. The paper will present forest kindergartens in Denmark and Croatia, and will analyze the advantages and disadvantages of these kindergartens compared to other kindergartens. Give guidelines for the implementation of the content of forest pedagogy in working with preschool children. Based on the studied literature, it was concluded that forest kindergartens provide preschool children with the possibility of greater stay of children in nature. The positive effects on children's psychophysical development are more pronounced compared to conventional kindergartens. In forest kindergartens, the contents of ecological education are more represented, which gives children a better foundation for a sustainable way of life. Forest kindergartens are insufficiently represented in the Republic of Croatia in relation to Denmark and in general.