Moving and Learning Outside (MLO) was an international action-research project that aimed at promoting the practice of outdoor education through a play-based and physical activity approach in preschools.The knowledge and scientific background about cultural differences regarding the approach to preschool learning processes between Northern and Southern European countries were the starting points to devise this project. In Northern countries, the preschool curriculum and practice are predominantly based in play and child led strategies, in which autonomy and the contact with natural environments are privileged. While in the South, the pedagogical practices are strongly defined by the pursuit of academic success and standardized adult led processes, which privilege indoor sitting activities to foster the learning of writing, reading and counting skills.Therefore, the underlying motivation behind the MLO project was to devise a set of practical tools that could be useful to change this paradigm, in order for children in preschools to use the outdoor as a place where they can learn and develop through outdoor play, autonomy, independent movement, contact with nature and their communities.The project involved 7 partners, from 5 countries, working as an organism where each part contributed to the whole, having a specific role. (1) The educational community- children as main actors, parents as informants, educators and caretakers as participating observers - kindergartens Naba from Estonia, Matije Gupca from Croatia, and Conquinha, Agrupamento de Escolas Madeira Torres, from Portugal, and the ONG Payzontas, from Greece. (2) The investigators who analyzed all results and transformed them in new practices and guidelines - Faculdade de Motricidade Humana, University of Lisbon, from Portugal and Queen Maud University College of Early Childhood Education, from Norway. (3) Local policy maker and disseminator actor – Torres Vedras Municipality, who allowed the results to reach schools, teachers, local community, parents, children and other stakeholders. The participants were selected based on the objectives of the project: preschool education, physical activity, play.The objectives were: -Drawing changes on the perceptions of policy makers, teachers, caretakers and parents on the possibilities of the outdoor as a rich and valuable environment for preschool children’s learning, development and well-being.-Improving pedagogical competences of preschool teachers and caretakers working with children in the outdoor environment, adopting physical activity and play based strategies.They were achieved through the implementation of different activities and tasks involving children, preschool staff members, parents and municipality staff:-Initial assessment: to enable the partners to make an initial diagnosis of the opportunities and perceptions regarding outdoor play in each preschool;-Create a Teacher’s Training Resources Pack (Output 1): that would empower teachers and caretakers with the knowledge and skills to implement a set of practices to enhance children’s physical activity and play in the outdoors.-Devise a set of 12 activities (Didactic-pedagogical Resources Pack for Teachers and Caretakers) based on the initial assessments to promote children’s physical, motor, social, emotional and cognitive development in the outdoors (Output 2).-Finally, define Outdoor Activities Guidelines and Recommendations for Preschool Education are presented (Output 3) to be made accessible online to researchers, teachers, practitioners, play advocates, organizations, municipalities, policy-makers and other relevant stakeholders who have an interest in promoting children’s outdoor play in educational settings.The creation of these 3 Outputs met the common purpose of changing adult perception regarding the benefits of outdoor play, making it possible to execute by anyone who wants to provide training for teacher and caretakers, foster a change of mentality in parents and in preschool staff and promote play-based and physical activity in preschools.It is possible to say that the participation level and quality of work carried out exceeded the initial level of expectations. The awareness of teachers/staff, parents and local community for the importance of outdoor play became an important discussion which will certainly continue in the futureMLO contributed to empower teachers, caretakers and educators to transform their daily practice with children, providing the preschool and staff with the necessary tools, skills and competences to improve and promote playing outdoor, allowing a change of mentality and paradigm in this matter and promoting a better and healthier lifestyle for the children, thus contributing to: 1) help preventing early school leaving, (2) improving children’s future academic results and (3) changing behaviors and adopting healthier life styles.