This paper explores teachers’ expected and perceived gains from classroom participation in design projects. The results indicate that teachers hope the experience will be fun for the children, and that it will increase both children’s and their own knowledge about technology. Although they consider learning goals important, these do not necessarily have to be communicated to the children, since the teachers experience that the children are learning several skills anyway. However, early involvement in the definition of learning goals could make participation more beneficial. The teachers also see several gains from partication for themselves, especially related to using a design approach in the classroom. We discuss the implications of these finding and suggest a way to increase the user gains for both children and teachers by considering the opportunity to use classroom participation as a way to support teachers’ competence development, thereby fulfilling the promise of mutual learning as advocated in Participatory Design.