As a result of the development of technology, the universal availability of its gifts and their constant use in everyday life, we spend more and more of our free time in front of mobile phones, computers, and televisions than in the open air, on the lap of Nature. Lack of contact with nature – especially in children – can cause problems that are collectively referred to as nature deficit disorder (Slovenian. motnja pomanjkanja narave). We are often unaware of the consequences of lack of contact with nature in the form various disorders, e.g., limitated use of the senses, difficulty concentrating, tendencies to gain weight and to suffer from physical and emotional diseases, insensitivity to issues related to environmental protection. In 2016, Ljubljana, a city that stands out in terms of economic growth, improving the quality of life of its inhabitants and protecting the environment, was awarded the title of European Green Capital by the European Commission. In her article, Maria Wtorkowska presents selected methods of preventing disorders related to lack of contact with nature undertaken in Slovenia among preschool- and early-school children. Wtorkowska discusses examples of good practice which are used, among other places, in the capital’s kindergartens, including the kindergarten Outside the Castle (Pod gradom) in Ljubljana, located in the center of Ljubljana, and effectively contribute to the prevention of disorders resulting from lack of contact with nature. She presents the activity of following institutions: the Institute of Forest Pedagogy(Inštitut za gozdno pedagogiko) and the Network of Slovenian Forest Kindergartens and Schools (Mreža gozdnih vrtcev in šol Slovenije) and the Špelinice Education and Counselling Institution (Zavod za izobraževanje in svetovanje Špelinice), founded by educator and anthropologist Špela Klofutar, which conducts a number of activities among nature with and for children, including Gozdne drobtinice, Naravoslovni nahrbtnik, Public Institution Small Street – Centre for Children and Families in Ljubljana (Javni zavod Mala ulica – Center za otroke in družine v Ljubljani) and its forest paths (Gozdna pot). A person who from early childhood experiences the world of nature as a developmental space, will in their adulthood consider it essential in future life, which will result in care for the environment. Therefore, by introducing educational programs in forest areas at the pre-school or early school stage, we prevent disorders caused by nature deficit more effectively than when we struggle with them. As our experience repeatedly shows, prevention is better than cure.