Forest School offers opportunities for children and young adults to come into regular contact with nature. Although, in relevant literature, Forest School is seen as highly conducive to participants' motivation to learn, there is no theoretical framework that examines how this motivation can be optimized in relation to Forest School pedagogy. Self-Determination Theory offers a broad perspective for motivational processes and will be used as a guide in this article to advance such a framework. Self-Determination Theory proposes that well-being, which has been identified as an aim of Forest School, is promoted through the support of three basic psychological needs for autonomy, competence and relatedness. In this conceptual article, we make links between Forest School pedagogical practices and Self-Determination Theory, mainly focusing on the support of children's basic psychological needs. Furthermore, we make suggestions for ways in which to enhance practice through explicit links with need-supportive teaching practices, as these are identified in the Self-Determination Theory literature.