The importance of finding ways to include a children’s perspective in urban planning is made clear by research pointing to inability among planners and decision-makers to take children’s interests into account, although children have relevant knowledge that they want to communicate. The aim of this study has been to develop a method, which can facilitate the process of bringing children’s knowledge of their local environment into the official planning process. We have investigated how 10-12 year-old children can map and write in a computerized Geographic Information System (GIS), the same system which constitutes the basis for spatial planning. The method also includes teachers, who map places and routes of interest for education. In order to attain a method that is simple, relevant and valid we have developed it through trials with five groups of children and teachers, and in discussions with planners.