Two teachers from a school in Copenhagen were allowed to move their third grade teaching into a forest every Thursday for three years. Thus 20% of the class's regular teaching took place in an outdoor environment. The purpose of the present study was to ask the children how they experienced lessons in the classroom and the forest settings. Therefore, two almost identical questionnaires including a total of 26 statements adjusted to each context were completed by the children four times from 2000 to 2003. Further, in the forest questionnaire three specific statements were added about the outdoor environment plus one question about their choice of playmates during breaks at school and breaks in the forest. Ten statements were categorized as "social relations", 14 statements as "teaching" and finally two related to "self-perceived physical activity". A significant difference (p less than 0.001) was found between the school/classroom and the outdoor environment when scores from all four questionnaires (2000-2003) were summed. The categories "social relations" (p less than 0.001), "teaching" (p less than 0.001) and "self-perceived physical activity" (p less than 0.001) all showed significant differences. It is concluded from the present case study that the combination of classroom and outdoor teaching, over a three-year period had a positive effect on the children's social relations, experience with teaching and self-perceived physical activity level. (Contains 5 tables and 3 figures.)